Crack The Coding Interview - Dinesh Varyani

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# Topic Question Difficulty

1 Array, Hash Table https://leetcode.com/problems/two-sum Easy

2 Hash Table, String, Sliding Window https://leetcode.com/problems/longest-substring-without-repeating-characters Medium
Array, Divide and Conquer, Dynamic
3 Programming https://leetcode.com/problems/maximum-subarray Easy
Array, Two Pointers, Dynamic
4 Programming, Stack, Monotonic Stack https://leetcode.com/problems/trapping-rain-water Hard
5 Linked List, Math, Recursion https://leetcode.com/problems/add-two-numbers Medium
6 Array, Two Pointers, Sorting https://leetcode.com/problems/3sum Medium
7 String, Dynamic Programming https://leetcode.com/problems/longest-palindromic-substring Medium
Array, Binary Search, Divide and
8 Conquer https://leetcode.com/problems/median-of-two-sorted-arrays Hard
9 Array, Two Pointers, Greedy https://leetcode.com/problems/container-with-most-water Medium
10 Array, Dynamic Programming https://leetcode.com/problems/best-time-to-buy-and-sell-stock Easy
11 Array, Binary Search https://leetcode.com/problems/search-in-rotated-sorted-array Medium
Array, Depth-First Search, Breadth-
12 First Search, Union Find, Matrix https://leetcode.com/problems/number-of-islands Medium
Hash Table, Linked List, Design,
13 Doubly-Linked List https://leetcode.com/problems/lru-cache Medium
14 Array, Sorting https://leetcode.com/problems/merge-intervals Medium
String, Dynamic Programming,
15 Backtracking https://leetcode.com/problems/generate-parentheses Medium
Array, Two Pointers, Binary Search,
16 Bit Manipulation https://leetcode.com/problems/find-the-duplicate-number Medium
17 Array, Prefix Sum https://leetcode.com/problems/product-of-array-except-self Medium
18 String, Stack https://leetcode.com/problems/valid-parentheses Easy
19 Array, Hash Table, Prefix Sum https://leetcode.com/problems/subarray-sum-equals-k Medium
20 Array, Dynamic Programming https://leetcode.com/problems/house-robber Medium
Array, Binary Search, Dynamic
21 Programming https://leetcode.com/problems/longest-increasing-subsequence Medium
22 Linked List, Recursion https://leetcode.com/problems/reverse-linked-list Easy
23 Array, Dynamic Programming https://leetcode.com/problems/maximum-product-subarray Medium
Linked List, Divide and Conquer, Heap
24 (Priority Queue), Merge Sort https://leetcode.com/problems/merge-k-sorted-lists Hard
25 Linked List, Recursion https://leetcode.com/problems/merge-two-sorted-lists Easy
Math, Dynamic Programming,
26 Memoization https://leetcode.com/problems/climbing-stairs Easy
Array, Dynamic Programming,
27 Breadth-First Search https://leetcode.com/problems/coin-change Medium
28 Array, Dynamic Programming, Greedy https://leetcode.com/problems/jump-game Medium
Hash Table, String, Dynamic
29 Programming, Trie, Memoization https://leetcode.com/problems/word-break Medium
30 Hash Table, String, Sliding Window https://leetcode.com/problems/minimum-window-substring Hard
31 Array, Binary Search https://leetcode.com/problems/find-first-and-last-position-of-element-in-sorted-array
Medium
32 Array, Backtracking https://leetcode.com/problems/permutations Medium
33 Array, Backtracking https://leetcode.com/problems/combination-sum Medium
34 Hash Table, String, Backtracking https://leetcode.com/problems/letter-combinations-of-a-phone-number Medium
Tree, Depth-First Search, Binary
35 Search Tree, Binary Tree https://leetcode.com/problems/validate-binary-search-tree Medium
Array, Queue, Sliding Window, Heap
36 (Priority Queue), Monotonic Queue https://leetcode.com/problems/sliding-window-maximum Hard
37 Tree, Depth-First Search, Binary Tree https://leetcode.com/problems/lowest-common-ancestor-of-a-binary-tree Medium
Tree, Depth-First Search, Breadth-First
38 Search, Binary Tree https://leetcode.com/problems/symmetric-tree Easy
39 Array, Two Pointers https://leetcode.com/problems/next-permutation Medium
40 Array, Two Pointers, Sorting https://leetcode.com/problems/sort-colors Medium
41 Linked List, Two Pointers https://leetcode.com/problems/remove-nth-node-from-end-of-list Medium
42 Array, Bit Manipulation https://leetcode.com/problems/single-number Easy
43 Array, Stack, Monotonic Stack https://leetcode.com/problems/largest-rectangle-in-histogram Hard
44 Array, Hash Table https://leetcode.com/problems/first-missing-positive Hard
Depth-First Search, Breadth-First
45 Search, Graph, Topological Sort https://leetcode.com/problems/course-schedule Medium
Dynamic Programming, Tree, Depth-
46 First Search, Binary Tree https://leetcode.com/problems/binary-tree-maximum-path-sum Hard
47 Array, Backtracking, Matrix https://leetcode.com/problems/word-search Medium
48 Array, Backtracking, Bit Manipulation https://leetcode.com/problems/subsets Medium
49 Array, Hash Table, Union Find https://leetcode.com/problems/longest-consecutive-sequence Medium
Array, Divide and Conquer, Sorting,
50 Heap (Priority Queue), Quickselect https://leetcode.com/problems/kth-largest-element-in-an-array Medium
 51 Hash Table, String, Sorting https://leetcode.com/problems/group-anagrams Medium
52 Array, Two Pointers https://leetcode.com/problems/move-zeroes Easy
53 Hash Table, Linked List, Two Pointers https://leetcode.com/problems/intersection-of-two-linked-lists Easy
Array, Hash Table, Divide and
54 Conquer, Sorting, Counting https://leetcode.com/problems/majority-element Easy
Math, Dynamic Programming,
55 Combinatorics https://leetcode.com/problems/unique-paths Medium
56 Array, Math, Matrix https://leetcode.com/problems/rotate-image Medium
Linked List, Two Pointers, Stack,
57 Recursion https://leetcode.com/problems/palindrome-linked-list Easy
58 String, Dynamic Programming https://leetcode.com/problems/edit-distance Hard
String, Dynamic Programming,
59 Recursion https://leetcode.com/problems/regular-expression-matching Hard
Array, Hash Table, Divide and
60 Conquer, Tree, Binary Tree https://leetcode.com/problems/construct-binary-tree-from-preorder-and-inorder-traversal
Medium
Tree, Depth-First Search, Breadth-First
61 Search, Binary Tree https://leetcode.com/problems/invert-binary-tree Easy
62 Array, Math, Two Pointers https://leetcode.com/problems/rotate-array Medium
63 String, Stack, Recursion https://leetcode.com/problems/decode-string Medium
64 Stack, Design https://leetcode.com/problems/min-stack Easy
Array, Hash Table, Divide and
Conquer, Sorting, Heap (Priority
Queue), Bucket Sort, Counting,
65 Quickselect https://leetcode.com/problems/top-k-frequent-elements Medium
66 Hash Table, Linked List https://leetcode.com/problems/copy-list-with-random-pointer Medium
67 String, Dynamic Programming, Stack https://leetcode.com/problems/longest-valid-parentheses Hard
68 Tree, Depth-First Search, Binary Tree https://leetcode.com/problems/path-sum-iii Medium
Tree, Breadth-First Search, Binary
69 Tree https://leetcode.com/problems/binary-tree-level-order-traversal Medium
70 Tree, Depth-First Search, Binary Tree https://leetcode.com/problems/diameter-of-binary-tree Easy
71 Array, Dynamic Programming, Greedy https://leetcode.com/problems/jump-game-ii Medium
72 Array, Dynamic Programming https://leetcode.com/problems/partition-equal-subset-sum Medium
Stack, Tree, Depth-First Search, Binary
73 Tree https://leetcode.com/problems/binary-tree-inorder-traversal Easy
Hash Table, String, Breadth-First
74 Search https://leetcode.com/problems/word-ladder Hard
Math, Dynamic Programming, Tree,
75 Binary Search Tree, Binary Tree https://leetcode.com/problems/unique-binary-search-trees Medium
76 Hash Table, Linked List, Two Pointers https://leetcode.com/problems/linked-list-cycle Easy
77 Array, Dynamic Programming, Matrix https://leetcode.com/problems/maximal-square Medium
78 String https://leetcode.com/problems/longest-common-prefix Easy
79 Array, Dynamic Programming, Greedy https://leetcode.com/problems/best-time-to-buy-and-sell-stock-ii Medium
80 Array, Dynamic Programming, Matrix https://leetcode.com/problems/minimum-path-sum Medium
Array, Binary Search, Divide and
81 Conquer, Matrix https://leetcode.com/problems/search-a-2d-matrix-ii Medium
82 Math https://leetcode.com/problems/reverse-integer Medium
83 Array, Binary Search https://leetcode.com/problems/search-insert-position Easy
Linked List, Stack, Tree, Depth-First
84 Search, Binary Tree https://leetcode.com/problems/flatten-binary-tree-to-linked-list Medium
85 Hash Table, String, Design, Trie https://leetcode.com/problems/implement-trie-prefix-tree Medium
86 Array, Stack, Monotonic Stack https://leetcode.com/problems/daily-temperatures Medium
Hash Table, Two Pointers, String,
87 Greedy https://leetcode.com/problems/partition-labels Medium
Math, Dynamic Programming, Breadth-
88 First Search https://leetcode.com/problems/perfect-squares Medium
89 String, Dynamic Programming https://leetcode.com/problems/decode-ways Medium
Two Pointers, Design, Sorting, Heap
90 (Priority Queue), Data Stream https://leetcode.com/problems/find-median-from-data-stream Hard
Array, Dynamic Programming, Stack,
91 Matrix, Monotonic Stack https://leetcode.com/problems/maximal-rectangle Hard
Array, Hash Table, Greedy, Sorting,
92 Heap (Priority Queue), Counting https://leetcode.com/problems/task-scheduler Medium
93 Linked List, Recursion https://leetcode.com/problems/reverse-nodes-in-k-group Hard
94 Array, Matrix, Simulation https://leetcode.com/problems/spiral-matrix Medium
Array, Dynamic Programming,
95 Backtracking https://leetcode.com/problems/target-sum Medium
96 Array, Hash Table https://leetcode.com/problems/find-all-numbers-disappeared-in-an-array Easy
Depth-First Search, Breadth-First
97 Search, Graph, Topological Sort https://leetcode.com/problems/course-schedule-ii Medium
Tree, Depth-First Search, Breadth-First
98 Search, Binary Tree https://leetcode.com/problems/merge-two-binary-trees Easy
String, Tree, Depth-First Search,
Breadth-First Search, Design, Binary
99 Tree https://leetcode.com/problems/serialize-and-deserialize-binary-tree Hard
100 Hash Table, Linked List, Two Pointers https://leetcode.com/problems/linked-list-cycle-ii Medium
 Dynamic Programming, Tree, Depth-
101 First Search, Binary Tree https://leetcode.com/problems/house-robber-iii Medium
Linked List, Two Pointers, Divide and
102 Conquer, Sorting, Merge Sort https://leetcode.com/problems/sort-list Medium
103 Hash Table, String, Sliding Window https://leetcode.com/problems/find-all-anagrams-in-a-string Medium
Tree, Depth-First Search, Breadth-First
104 Search, Binary Tree https://leetcode.com/problems/binary-tree-right-side-view Medium
105 String, Dynamic Programming https://leetcode.com/problems/palindromic-substrings Medium
Tree, Depth-First Search, Breadth-First
106 Search, Binary Tree https://leetcode.com/problems/maximum-depth-of-binary-tree Easy
107 Array, Breadth-First Search, Matrix https://leetcode.com/problems/rotting-oranges Medium
108 Array, Hash Table, Matrix https://leetcode.com/problems/set-matrix-zeroes Medium
Array, Divide and Conquer, Tree,
109 Binary Search Tree, Binary Tree https://leetcode.com/problems/convert-sorted-array-to-binary-search-tree Easy
110 Array, Binary Search, Matrix https://leetcode.com/problems/search-a-2d-matrix Medium
111 Array, Binary Search https://leetcode.com/problems/find-minimum-in-rotated-sorted-array Medium
Tree, Depth-First Search, Breadth-First
112 Search, Binary Tree https://leetcode.com/problems/populating-next-right-pointers-in-each-node Medium
113 Array, Two Pointers https://leetcode.com/problems/remove-duplicates-from-sorted-array Easy
Tree, Depth-First Search, Binary
114 Search Tree, Binary Tree https://leetcode.com/problems/kth-smallest-element-in-a-bst Medium
Array, Binary Search, Sliding Window,
115 Prefix Sum https://leetcode.com/problems/minimum-size-subarray-sum Medium
116 Array, Hash Table https://leetcode.com/problems/find-all-duplicates-in-an-array Medium
117 Array, Dynamic Programming https://leetcode.com/problems/burst-balloons Hard
Dynamic Programming, Bit
118 Manipulation https://leetcode.com/problems/counting-bits Easy
Tree, Depth-First Search, Breadth-First
119 Search, Binary Tree https://leetcode.com/problems/all-nodes-distance-k-in-binary-tree Medium
120 Linked List, Recursion https://leetcode.com/problems/swap-nodes-in-pairs Medium
121 Linked List https://leetcode.com/problems/reverse-linked-list-ii Medium
Array, String, Backtracking, Trie,
122 Matrix https://leetcode.com/problems/word-search-ii Hard
123 String, Dynamic Programming https://leetcode.com/problems/longest-common-subsequence Medium
Array, Binary Search, Sorting, Heap
124 (Priority Queue), Matrix https://leetcode.com/problems/kth-smallest-element-in-a-sorted-matrix Medium
125 Array, Two Pointers, Sorting https://leetcode.com/problems/4sum Medium
126 Array, Dynamic Programming https://leetcode.com/problems/best-time-to-buy-and-sell-stock-iii Hard
127 Array, Dynamic Programming https://leetcode.com/problems/best-time-to-buy-and-sell-stock-with-cooldown Medium
String, Dynamic Programming,
128 Backtracking https://leetcode.com/problems/palindrome-partitioning Medium
Linked List, Two Pointers, Stack,
129 Recursion https://leetcode.com/problems/reorder-list Medium
130 Array, Dynamic Programming https://leetcode.com/problems/min-cost-climbing-stairs Easy
Array, Depth-First Search, Breadth-
131 First Search, Union Find, Matrix https://leetcode.com/problems/max-area-of-island Medium
Array, Binary Search, Divide and
Conquer, Binary Indexed Tree,
Segment Tree, Merge Sort, Ordered
132 Set https://leetcode.com/problems/count-of-smaller-numbers-after-self Hard
133 Array, Two Pointers, Sorting https://leetcode.com/problems/3sum-closest Medium
Tree, Breadth-First Search, Binary
134 Tree https://leetcode.com/problems/binary-tree-zigzag-level-order-traversal Medium
135 Array, Binary Search https://leetcode.com/problems/find-peak-element Medium
Array, Hash Table, Math, Design,
136 Randomized https://leetcode.com/problems/insert-delete-getrandom-o1 Medium
137 Tree, Depth-First Search, Binary Tree https://leetcode.com/problems/balanced-binary-tree Easy
138 Math https://leetcode.com/problems/palindrome-number Easy
139 Array, Backtracking https://leetcode.com/problems/n-queens Hard
Array, Math, Divide and Conquer,
Geometry, Sorting, Heap (Priority
140 Queue), Quickselect https://leetcode.com/problems/k-closest-points-to-origin Medium
141 Linked List https://leetcode.com/problems/odd-even-linked-list Medium
Depth-First Search, Breadth-First
142 Search, Graph, Topological Sort https://leetcode.com/problems/minimum-height-trees Medium
Tree, Depth-First Search, Breadth-First
143 Search, Binary Tree https://leetcode.com/problems/same-tree Easy
Tree, Depth-First Search, Binary
144 Search Tree, Binary Tree https://leetcode.com/problems/lowest-common-ancestor-of-a-binary-search-tree Easy
Array, Two Pointers, Stack, Greedy,
145 Sorting, Monotonic Stack https://leetcode.com/problems/shortest-unsorted-continuous-subarray Medium
Stack, Tree, Design, Binary Search
146 Tree, Binary Tree, Iterator https://leetcode.com/problems/binary-search-tree-iterator Medium
Dynamic Programming, Depth-First
Search, Breadth-First Search, Graph,
147 Topological Sort, Memoization https://leetcode.com/problems/longest-increasing-path-in-a-matrix Hard
148 Array, Greedy, Sorting https://leetcode.com/problems/queue-reconstruction-by-height Medium
149 Tree, Depth-First Search, Binary Tree https://leetcode.com/problems/path-sum Easy
150 Tree, Binary Search Tree, Binary Tree https://leetcode.com/problems/delete-node-in-a-bst Medium
Tree, Depth-First Search, String
151 Matching, Binary Tree, Hash Function https://leetcode.com/problems/subtree-of-another-tree Easy
Array, Hash Table, Math, Bit
152 Manipulation, Sorting https://leetcode.com/problems/missing-number Easy
153 String, Dynamic Programming https://leetcode.com/problems/longest-palindromic-subsequence Medium
Array, Depth-First Search, Breadth-
First Search, Union Find, Graph,
154 Shortest Path https://leetcode.com/problems/evaluate-division Medium
155 Array, Dynamic Programming https://leetcode.com/problems/house-robber-ii Medium
156 Array, Dynamic Programming https://leetcode.com/problems/pascals-triangle Easy
Hash Table, Depth-First Search,
157 Breadth-First Search, Graph https://leetcode.com/problems/clone-graph Medium
158 Array, Dynamic Programming https://leetcode.com/problems/coin-change-2 Medium
159 Hash Table, Math, Two Pointers https://leetcode.com/problems/happy-number Easy
Depth-First Search, Breadth-First
160 Search, Union Find, Graph https://leetcode.com/problems/number-of-provinces Medium
161 Array, Binary Search https://leetcode.com/problems/single-element-in-a-sorted-array Medium
162 Array, Greedy https://leetcode.com/problems/gas-station Medium
Dynamic Programming, Backtracking,
163 Tree, Binary Search Tree, Binary Tree https://leetcode.com/problems/unique-binary-search-trees-ii Medium
Dynamic Programming, Depth-First
Search, Breadth-First Search, Graph,
164 Heap (Priority Queue), Shortest Path https://leetcode.com/problems/cheapest-flights-within-k-stops Medium
165 Linked List, Two Pointers https://leetcode.com/problems/middle-of-the-linked-list Easy
String, Stack, Greedy, Monotonic
166 Stack https://leetcode.com/problems/remove-k-digits Medium
167 Array, Backtracking, Matrix https://leetcode.com/problems/sudoku-solver Hard
Array, Depth-First Search, Breadth-
168 First Search, Union Find, Matrix https://leetcode.com/problems/surrounded-regions Medium
Binary Search, Tree, Depth-First
169 Search, Binary Tree https://leetcode.com/problems/count-complete-tree-nodes Medium
String, Backtracking, Breadth-First
170 Search https://leetcode.com/problems/remove-invalid-parentheses Hard
Array, Dynamic Programming,
Backtracking, Bit Manipulation,
171 Memoization, Bitmask https://leetcode.com/problems/partition-to-k-equal-sum-subsets Medium
172 Array, Two Pointers, Binary Search https://leetcode.com/problems/two-sum-ii-input-array-is-sorted Easy
173 Hash Table, String, Queue, Counting https://leetcode.com/problems/first-unique-character-in-a-string Easy
174 String, Greedy, Sorting https://leetcode.com/problems/largest-number Medium
Array, Math, Enumeration, Number
175 Theory https://leetcode.com/problems/count-primes Medium
176 Array, Two Pointers, Sorting https://leetcode.com/problems/squares-of-a-sorted-array Easy
177 Array, Backtracking https://leetcode.com/problems/permutations-ii Medium
Hash Table, String, Dynamic
Programming, Backtracking, Trie,
178 Memoization https://leetcode.com/problems/word-break-ii Hard
179 Array, Backtracking https://leetcode.com/problems/combination-sum-ii Medium
180 Array, Dynamic Programming https://leetcode.com/problems/triangle Medium
181 Linked List, Recursion https://leetcode.com/problems/remove-linked-list-elements Easy
182 Linked List, Two Pointers https://leetcode.com/problems/remove-duplicates-from-sorted-list-ii Medium
183 Array, Hash Table, Matrix https://leetcode.com/problems/valid-sudoku Medium
Backtracking, Tree, Depth-First
184 Search, Binary Tree https://leetcode.com/problems/path-sum-ii Medium
Linked List, Divide and Conquer, Tree,
185 Binary Search Tree, Binary Tree https://leetcode.com/problems/convert-sorted-list-to-binary-search-tree Medium
186 Array https://leetcode.com/problems/insert-interval Medium
String, Dynamic Programming,
187 Greedy, Recursion https://leetcode.com/problems/wildcard-matching Hard
188 Array, Backtracking, Bit Manipulation https://leetcode.com/problems/subsets-ii Medium
189 Array, Dynamic Programming, Matrix https://leetcode.com/problems/unique-paths-ii Medium
Array, Binary Search, Dynamic
190 Programming, Greedy https://leetcode.com/problems/split-array-largest-sum Hard
Hash Table, String, Greedy, Sorting,
191 Heap (Priority Queue), Counting https://leetcode.com/problems/reorganize-string Medium
Hash Table, Two Pointers, String,
192 Sliding Window https://leetcode.com/problems/permutation-in-string Medium
193 Array, Hash Table, Sorting, Counting https://leetcode.com/problems/majority-element-ii Medium
Array, Hash Table, Divide and
194 Conquer, Tree, Binary Tree https://leetcode.com/problems/construct-binary-tree-from-inorder-and-postorder-traversal
Medium
195 Array, Dynamic Programming https://leetcode.com/problems/minimum-cost-for-tickets Medium
 Hash Table, String, Trie, Sorting, Heap
(Priority Queue), Bucket Sort,
196 Counting https://leetcode.com/problems/top-k-frequent-words Medium
Array, Depth-First Search, Breadth-
197 First Search, Matrix https://leetcode.com/problems/island-perimeter Easy
198 Linked List https://leetcode.com/problems/remove-duplicates-from-sorted-list Easy
Math, String, Bit Manipulation,
199 Simulation https://leetcode.com/problems/add-binary Easy
Array, Dynamic Programming,
200 Breadth-First Search, Matrix https://leetcode.com/problems/01-matrix Medium
201 Hash Table, String, Sorting https://leetcode.com/problems/valid-anagram Easy
202 Math, String, Simulation https://leetcode.com/problems/multiply-strings Medium
203 Binary Search, Interactive https://leetcode.com/problems/first-bad-version Easy
String, Depth-First Search, Design,
204 Trie https://leetcode.com/problems/design-add-and-search-words-data-structure Medium
205 Array, Stack, Monotonic Stack https://leetcode.com/problems/next-greater-element-ii Medium
206 Math, String, Stack https://leetcode.com/problems/basic-calculator-ii Medium
Array, String, Depth-First Search,
207 Breadth-First Search, Union Find https://leetcode.com/problems/accounts-merge Medium
208 Two Pointers, String, Greedy https://leetcode.com/problems/valid-palindrome-ii Easy
209 Linked List https://leetcode.com/problems/delete-node-in-a-linked-list Easy
210 Array, Two Pointers https://leetcode.com/problems/interval-list-intersections Medium
211 Linked List, Two Pointers https://leetcode.com/problems/rotate-list Medium
212 Tree, Depth-First Search, Binary Tree https://leetcode.com/problems/sum-root-to-leaf-numbers Medium
213 Array, Dynamic Programming, Matrix https://leetcode.com/problems/dungeon-game Hard
214 Math, Recursion https://leetcode.com/problems/powx-n Medium
Array, Binary Search, Sliding Window,
215 Prefix Sum https://leetcode.com/problems/max-consecutive-ones-iii Medium
Array, Hash Table, Two Pointers,
216 Binary Search, Sorting https://leetcode.com/problems/intersection-of-two-arrays-ii Easy
String, Stack, Greedy, Monotonic
217 Stack https://leetcode.com/problems/remove-duplicate-letters Medium
Tree, Depth-First Search, Binary
218 Search Tree, Binary Tree https://leetcode.com/problems/recover-binary-search-tree Medium
Depth-First Search, Breadth-First
219 Search, Union Find, Graph https://leetcode.com/problems/is-graph-bipartite Medium
220 Array, Hash Table, Prefix Sum https://leetcode.com/problems/contiguous-array Medium
Array, Two Pointers, Binary Search,
221 Sorting, Heap (Priority Queue) https://leetcode.com/problems/find-k-closest-elements Medium
222 Two Pointers, String, Recursion https://leetcode.com/problems/reverse-string Easy
Tree, Depth-First Search, Binary
223 Search Tree, Binary Tree https://leetcode.com/problems/range-sum-of-bst Easy
Hash Table, String, Sorting, Heap
(Priority Queue), Bucket Sort,
224 Counting https://leetcode.com/problems/sort-characters-by-frequency Medium
225 Hash Table, String, Sliding Window https://leetcode.com/problems/longest-repeating-character-replacement Medium
Stack, Tree, Depth-First Search, Binary
226 Tree https://leetcode.com/problems/binary-tree-postorder-traversal Easy
227 Array, Bit Manipulation https://leetcode.com/problems/single-number-ii Medium
Hash Table, Math, Dynamic
228 Programming, Heap (Priority Queue) https://leetcode.com/problems/ugly-number-ii Medium
Depth-First Search, Graph, Eulerian
229 Circuit https://leetcode.com/problems/reconstruct-itinerary Hard
Array, Divide and Conquer, Binary
Indexed Tree, Segment Tree, Line
Sweep, Heap (Priority Queue), Ordered
230 Set https://leetcode.com/problems/the-skyline-problem Hard
231 Array, Bit Manipulation https://leetcode.com/problems/single-number-iii Medium
Two Pointers, String, Dynamic
232 Programming https://leetcode.com/problems/is-subsequence Easy
Depth-First Search, Breadth-First
Search, Graph, Heap (Priority Queue),
233 Shortest Path https://leetcode.com/problems/network-delay-time Medium
String, Tree, Depth-First Search,
234 Binary Tree https://leetcode.com/problems/binary-tree-paths Easy
Hash Table, String, Divide and
235 Conquer, Sliding Window https://leetcode.com/problems/longest-substring-with-at-least-k-repeating-characters
Medium
Tree, Depth-First Search, Breadth-First
236 Search, Binary Tree https://leetcode.com/problems/minimum-depth-of-binary-tree Easy
237 Array, Dynamic Programming, Greedy https://leetcode.com/problems/best-time-to-buy-and-sell-stock-with-transaction-fee
Medium
238 Array https://leetcode.com/problems/non-decreasing-array Medium
239 String, Dynamic Programming https://leetcode.com/problems/interleaving-string Medium
240 Array, Matrix, Simulation https://leetcode.com/problems/game-of-life Medium
241 Array, Backtracking https://leetcode.com/problems/combinations Medium
Stack, Tree, Depth-First Search, Binary
242 Tree https://leetcode.com/problems/binary-tree-preorder-traversal Easy
 Backtracking, Depth-First Search,
243 Breadth-First Search, Graph https://leetcode.com/problems/all-paths-from-source-to-target Medium
244 Array, Math https://leetcode.com/problems/plus-one Easy
245 Array, Dynamic Programming https://leetcode.com/problems/best-time-to-buy-and-sell-stock-iv Hard
246 Array, Greedy https://leetcode.com/problems/increasing-triplet-subsequence Medium
Tree, Depth-First Search, Binary
247 Search Tree, Binary Tree https://leetcode.com/problems/trim-a-binary-search-tree Medium
Two Pointers, String, Stack,
248 Simulation https://leetcode.com/problems/backspace-string-compare Easy
Array, Binary Search, Dynamic
Programming, Sliding Window, Rolling
249 Hash, Hash Function https://leetcode.com/problems/maximum-length-of-repeated-subarray Medium
250 Array, Binary Search, Greedy https://leetcode.com/problems/capacity-to-ship-packages-within-d-days Medium
251 Two Pointers, String, String Matching https://leetcode.com/problems/implement-strstr Easy
Hash Table, String, Backtracking,
252 Breadth-First Search https://leetcode.com/problems/word-ladder-ii Hard
253 Array, Sliding Window https://leetcode.com/problems/subarray-product-less-than-k Medium
254 Array, Hash Table, Sorting https://leetcode.com/problems/contains-duplicate Easy
Linked List, Depth-First Search,
255 Doubly-Linked List https://leetcode.com/problems/flatten-a-multilevel-doubly-linked-list Medium
Tree, Depth-First Search, Breadth-First
256 Search, Binary Tree https://leetcode.com/problems/populating-next-right-pointers-in-each-node-ii Medium
Array, Divide and Conquer, Stack,
257 Tree, Monotonic Stack, Binary Tree https://leetcode.com/problems/maximum-binary-tree Medium
258 String, Stack https://leetcode.com/problems/minimum-remove-to-make-valid-parentheses Medium
259 Tree, Depth-First Search, Binary Tree https://leetcode.com/problems/distribute-coins-in-binary-tree Medium
Depth-First Search, Graph,
260 Biconnected Component https://leetcode.com/problems/critical-connections-in-a-network Hard
261 Math, String, Stack, Recursion https://leetcode.com/problems/basic-calculator Hard
Depth-First Search, Breadth-First
262 Search, Union Find, Graph https://leetcode.com/problems/redundant-connection Medium
263 Hash Table, String https://leetcode.com/problems/jewels-and-stones Easy
Array, Dynamic Programming, Greedy,
264 Sorting https://leetcode.com/problems/non-overlapping-intervals Medium
Array, Depth-First Search, Breadth-
265 First Search, Matrix https://leetcode.com/problems/flood-fill Easy
266 String https://leetcode.com/problems/zigzag-conversion Medium
Tree, Depth-First Search, Breadth-First
267 Search, Binary Tree https://leetcode.com/problems/maximum-width-of-binary-tree Medium
268 Math, Recursion https://leetcode.com/problems/permutation-sequence Hard
Array, Stack, Tree, Binary Search Tree,
269 Monotonic Stack, Binary Tree https://leetcode.com/problems/construct-binary-search-tree-from-preorder-traversal
Medium
Math, String, Dynamic Programming,
270 Recursion, Memoization https://leetcode.com/problems/different-ways-to-add-parentheses Medium
271 Array, Binary Search https://leetcode.com/problems/search-in-rotated-sorted-array-ii Medium
272 Linked List, Math, Stack https://leetcode.com/problems/add-two-numbers-ii Medium
Hash Table, Two Pointers, Tree, Depth-
First Search, Breadth-First Search,
273 Binary Search Tree, Binary Tree https://leetcode.com/problems/two-sum-iv-input-is-a-bst Easy
Tree, Depth-First Search, Binary
274 Search Tree, Binary Tree https://leetcode.com/problems/convert-bst-to-greater-tree Medium
275 Linked List, Two Pointers https://leetcode.com/problems/partition-list Medium
276 Math, Binary Search https://leetcode.com/problems/sqrtx Easy
277 Hash Table, String https://leetcode.com/problems/isomorphic-strings Easy
Array, Dynamic Programming, Binary
278 Indexed Tree, Segment Tree https://leetcode.com/problems/number-of-longest-increasing-subsequence Medium
279 Array, Binary Search https://leetcode.com/problems/binary-search Easy
String, Dynamic Programming, Stack,
280 Greedy https://leetcode.com/problems/valid-parenthesis-string Medium
281 String, String Matching https://leetcode.com/problems/repeated-substring-pattern Easy
282 Array, Two Pointers https://leetcode.com/problems/remove-element Easy
283 Array, Dynamic Programming https://leetcode.com/problems/combination-sum-iv Medium
284 String, Dynamic Programming https://leetcode.com/problems/distinct-subsequences Hard
285 Array, Stack https://leetcode.com/problems/asteroid-collision Medium
Array, Math, Dynamic Programming,
286 Sorting https://leetcode.com/problems/largest-divisible-subset Medium
Array, Depth-First Search, Breadth-
287 First Search, Matrix https://leetcode.com/problems/pacific-atlantic-water-flow Medium
Array, Binary Search, Stack,
288 Monotonic Stack, Ordered Set https://leetcode.com/problems/132-pattern Medium
Array, Hash Table, Dynamic
289 Programming https://leetcode.com/problems/delete-and-earn Medium
Array, Dynamic Programming, Stack,
290 Monotonic Stack https://leetcode.com/problems/sum-of-subarray-minimums Medium
291 Array, Dynamic Programming, Matrix https://leetcode.com/problems/count-square-submatrices-with-all-ones Medium
292 String, Dynamic Programming https://leetcode.com/problems/palindrome-partitioning-ii Hard
Tree, Depth-First Search, Breadth-First
293 Search, Binary Tree https://leetcode.com/problems/sum-of-left-leaves Easy
294 Bit Manipulation https://leetcode.com/problems/hamming-distance Easy
Stack, Tree, Depth-First Search,
295 Design, Queue, Iterator https://leetcode.com/problems/flatten-nested-list-iterator Medium
296 String, Stack https://leetcode.com/problems/score-of-parentheses Medium
Array, Hash Table, Two Pointers,
297 String, Dynamic Programming https://leetcode.com/problems/longest-string-chain Medium
298 Two Pointers, String https://leetcode.com/problems/valid-palindrome Easy
299 Tree, Depth-First Search, Binary Tree https://leetcode.com/problems/longest-univalue-path Medium
300 String, Backtracking, Bit Manipulation https://leetcode.com/problems/letter-case-permutation Medium
Tree, Breadth-First Search, Binary
301 Tree https://leetcode.com/problems/binary-tree-level-order-traversal-ii Medium
Tree, Depth-First Search, Breadth-First
302 Search, Binary Tree https://leetcode.com/problems/find-duplicate-subtrees Medium
Dynamic Programming, Stack, Greedy,
303 Monotonic Stack https://leetcode.com/problems/minimum-cost-tree-from-leaf-values Medium
Hash Table, Linked List, Design,
304 Doubly-Linked List https://leetcode.com/problems/lfu-cache Hard
Array, Binary Search, Dynamic
305 Programming, Sorting https://leetcode.com/problems/russian-doll-envelopes Hard
Array, Binary Search, Dynamic
306 Programming, Sorting https://leetcode.com/problems/maximum-profit-in-job-scheduling Hard
307 Math, String, Simulation https://leetcode.com/problems/add-strings Easy
308 Array, Hash Table, Counting https://leetcode.com/problems/pairs-of-songs-with-total-durations-divisible-by-60Medium
309 Stack, Design, Queue https://leetcode.com/problems/implement-queue-using-stacks Easy
Array, Hash Table, Bit Manipulation,
310 Trie https://leetcode.com/problems/maximum-xor-of-two-numbers-in-an-array Medium
311 Hash Table, Math, String https://leetcode.com/problems/roman-to-integer Easy
312 Array, Hash Table, Graph https://leetcode.com/problems/find-the-town-judge Easy
313 Array, Heap (Priority Queue) https://leetcode.com/problems/find-k-pairs-with-smallest-sums Medium
314 Array, Two Pointers, Sorting https://leetcode.com/problems/merge-sorted-array Easy
315 String, Stack https://leetcode.com/problems/remove-all-adjacent-duplicates-in-string Easy
316 Two Pointers, String https://leetcode.com/problems/reverse-words-in-a-string Medium
317 Array, Hash Table https://leetcode.com/problems/4sum-ii Medium
Tree, Depth-First Search, Breadth-First
318 Search, Binary Tree https://leetcode.com/problems/average-of-levels-in-binary-tree Easy
319 Array, Prefix Sum https://leetcode.com/problems/find-pivot-index Easy
320 Array, Hash Table, Sorting, Counting https://leetcode.com/problems/how-many-numbers-are-smaller-than-the-current-number
Easy
321 Hash Table, Math, String https://leetcode.com/problems/integer-to-roman Medium
Depth-First Search, Breadth-First
322 Search, Graph https://leetcode.com/problems/keys-and-rooms Medium
323 Math, Bit Manipulation, Recursion https://leetcode.com/problems/power-of-two Easy
Array, Hash Table, Sliding Window,
324 Counting https://leetcode.com/problems/subarrays-with-k-different-integers Hard
Array, Math, Dynamic Programming,
325 Recursion, Game Theory https://leetcode.com/problems/predict-the-winner Medium
Array, Divide and Conquer, Dynamic
Programming, Queue, Monotonic
326 Queue https://leetcode.com/problems/maximum-sum-circular-subarray Medium
Math, Dynamic Programming,
327 Recursion, Memoization https://leetcode.com/problems/fibonacci-number Easy
328 Divide and Conquer, Bit Manipulation https://leetcode.com/problems/reverse-bits Easy
329 Tree, Depth-First Search, Binary Tree https://leetcode.com/problems/delete-nodes-and-return-forest Medium
Array, Binary Search, Queue, Sliding
Window, Heap (Priority Queue), Prefix
330 Sum, Monotonic Queue https://leetcode.com/problems/shortest-subarray-with-sum-at-least-k Hard
331 Array, Binary Search https://leetcode.com/problems/find-minimum-in-rotated-sorted-array-ii Hard
332 Hash Table, String https://leetcode.com/problems/word-pattern Easy
333 Array, Dynamic Programming https://leetcode.com/problems/arithmetic-slices Medium
334 Array, String, Dynamic Programming https://leetcode.com/problems/ones-and-zeroes Medium
Array, Backtracking, Bit Manipulation,
335 Matrix https://leetcode.com/problems/unique-paths-iii Hard
Array, Design, Binary Indexed Tree,
336 Segment Tree https://leetcode.com/problems/range-sum-query-mutable Medium
Hash Table, Tree, Depth-First Search,
337 Breadth-First Search, Binary Tree https://leetcode.com/problems/vertical-order-traversal-of-a-binary-tree Hard
338 Array, Greedy https://leetcode.com/problems/candy Hard
339 Array, Two Pointers https://leetcode.com/problems/remove-duplicates-from-sorted-array-ii Medium
340 Hash Table, String, Trie, Sorting https://leetcode.com/problems/number-of-matching-subsequences Medium
341 Array, Binary Search https://leetcode.com/problems/koko-eating-bananas Medium
Array, Hash Table, String, Breadth-
342 First Search https://leetcode.com/problems/open-the-lock Medium
 String, Tree, Depth-First Search,
Breadth-First Search, Design, Binary
343 Search Tree, Binary Tree https://leetcode.com/problems/serialize-and-deserialize-bst Medium
344 Array, Backtracking https://leetcode.com/problems/combination-sum-iii Medium
345 Array, Hash Table, String, Trie https://leetcode.com/problems/palindrome-pairs Hard
346 Array, Hash Table, String https://leetcode.com/problems/verifying-an-alien-dictionary Easy
347 Array, Math, Stack https://leetcode.com/problems/evaluate-reverse-polish-notation Medium
Array, Breadth-First Search, Heap
348 (Priority Queue), Matrix https://leetcode.com/problems/trapping-rain-water-ii Hard
349 Array, Sliding Window, Prefix Sum https://leetcode.com/problems/maximum-points-you-can-obtain-from-cards Medium
Tree, Depth-First Search, Breadth-First
350 Search, Binary Tree https://leetcode.com/problems/cousins-in-binary-tree Easy
351 Math, Bit Manipulation https://leetcode.com/problems/divide-two-integers Medium
352 String, Dynamic Programming https://leetcode.com/problems/delete-operation-for-two-strings Medium
353 Array, Greedy, Sorting https://leetcode.com/problems/minimum-number-of-arrows-to-burst-balloons Medium
354 Array, Hash Table, Prefix Sum https://leetcode.com/problems/subarray-sums-divisible-by-k Medium
355 Two Pointers, String https://leetcode.com/problems/count-binary-substrings Easy
356 String, Backtracking https://leetcode.com/problems/restore-ip-addresses Medium
357 Array, Matrix, Simulation https://leetcode.com/problems/spiral-matrix-ii Medium
Hash Table, Stack, Design, Ordered
358 Set https://leetcode.com/problems/maximum-frequency-stack Hard
359 Math, Dynamic Programming https://leetcode.com/problems/integer-break Medium
360 Array, Two Pointers, Sorting https://leetcode.com/problems/sort-array-by-parity Easy
Dynamic Programming, Tree, Depth-
361 First Search, Binary Tree https://leetcode.com/problems/binary-tree-cameras Hard
362 Array, Dynamic Programming, Greedy https://leetcode.com/problems/wiggle-subsequence Medium
Array, Depth-First Search, Breadth-
363 First Search https://leetcode.com/problems/jump-game-iii Medium
364 Bit Manipulation https://leetcode.com/problems/number-of-1-bits Easy
365 Tree, Binary Search Tree, Binary Tree https://leetcode.com/problems/insert-into-a-binary-search-tree Medium
366 Array, Math, Sorting https://leetcode.com/problems/maximum-product-of-three-numbers Easy
367 Math, String, Backtracking https://leetcode.com/problems/expression-add-operators Hard
368 Math, String https://leetcode.com/problems/excel-sheet-column-title Easy
Array, Binary Search, Divide and
Conquer, Binary Indexed Tree,
Segment Tree, Merge Sort, Ordered
369 Set https://leetcode.com/problems/reverse-pairs Hard
Dynamic Programming, Tree, Depth-
370 First Search, Graph https://leetcode.com/problems/sum-of-distances-in-tree Hard
371 Array, Greedy, Sorting https://leetcode.com/problems/two-city-scheduling Medium
372 String, Stack https://leetcode.com/problems/remove-all-adjacent-duplicates-in-string-ii Medium
373 Array, Design, Matrix, Prefix Sum https://leetcode.com/problems/range-sum-query-2d-immutable Medium
374 Math, Dynamic Programming https://leetcode.com/problems/2-keys-keyboard Medium
Array, Hash Table, Two Pointers,
375 Binary Search, Sorting https://leetcode.com/problems/intersection-of-two-arrays Easy
376 Array, Stack, Simulation https://leetcode.com/problems/validate-stack-sequences Medium
377 Hash Table, String, Greedy https://leetcode.com/problems/longest-palindrome Easy
378 Tree, Binary Search Tree, Binary Tree https://leetcode.com/problems/search-in-a-binary-search-tree Easy
Array, Dynamic Programming, Greedy,
379 Heap (Priority Queue) https://leetcode.com/problems/minimum-number-of-refueling-stops Hard
Array, Two Pointers, Binary Search,
380 Greedy, Sorting https://leetcode.com/problems/valid-triangle-number Medium
Dynamic Programming, Tree,
381 Recursion, Memoization, Binary Tree https://leetcode.com/problems/all-possible-full-binary-trees Medium
382 Two Pointers, String https://leetcode.com/problems/reverse-words-in-a-string-iii Easy
383 Math, String https://leetcode.com/problems/excel-sheet-column-number Easy
384 Array, Dynamic Programming, Matrix https://leetcode.com/problems/cherry-pickup Hard
Array, Hash Table, Linked List, Design,
385 Hash Function https://leetcode.com/problems/design-hashmap Easy
386 Tree, Depth-First Search, Binary Tree https://leetcode.com/problems/binary-tree-pruning Medium
387 Math, Bit Manipulation https://leetcode.com/problems/sum-of-two-integers Medium
Stack, Design, Monotonic Stack, Data
388 Stream https://leetcode.com/problems/online-stock-span Medium
389 Linked List, Math https://leetcode.com/problems/convert-binary-number-in-a-linked-list-to-integer Easy
Tree, Depth-First Search, Binary
390 Search Tree, Binary Tree https://leetcode.com/problems/binary-search-tree-to-greater-sum-tree Medium
391 Array https://leetcode.com/problems/max-consecutive-ones Easy
392 Array, Prefix Sum https://leetcode.com/problems/running-sum-of-1d-array Easy
393 Math, Greedy https://leetcode.com/problems/maximum-swap Medium
String, Rolling Hash, String Matching,
394 Hash Function https://leetcode.com/problems/shortest-palindrome Hard
395 Depth-First Search, Union Find, Graph https://leetcode.com/problems/most-stones-removed-with-same-row-or-column Medium
396 Tree, Depth-First Search, Binary Tree https://leetcode.com/problems/maximum-difference-between-node-and-ancestorMedium
397 Array, Dynamic Programming https://leetcode.com/problems/frog-jump Hard
398 Array, Dynamic Programming https://leetcode.com/problems/pascals-triangle-ii Easy
Tree, Depth-First Search, Breadth-First
399 Search, Binary Tree https://leetcode.com/problems/deepest-leaves-sum Medium
Array, Depth-First Search, Breadth-
400 First Search, Matrix https://leetcode.com/problems/shortest-bridge Medium
401 Bit Manipulation https://leetcode.com/problems/bitwise-and-of-numbers-range Medium
Math, Binary Search, Dynamic
402 Programming https://leetcode.com/problems/super-egg-drop Hard
Array, Sliding Window, Sorting, Bucket
403 Sort, Ordered Set https://leetcode.com/problems/contains-duplicate-iii Medium
404 Math, String, Simulation https://leetcode.com/problems/robot-bounded-in-circle Medium
Stack, Tree, Depth-First Search, Binary
405 Search Tree, Binary Tree https://leetcode.com/problems/increasing-order-search-tree Easy
406 Array, Hash Table, String https://leetcode.com/problems/find-common-characters Easy
407 Array, Two Pointers, String https://leetcode.com/problems/shortest-distance-to-a-character Easy
408 Array, Greedy https://leetcode.com/problems/can-place-flowers Easy
409 Array, Hash Table, Sliding Window https://leetcode.com/problems/contains-duplicate-ii Easy
410 Array, Hash Table, Math, Counting https://leetcode.com/problems/number-of-good-pairs Easy
411 String, Stack, Greedy https://leetcode.com/problems/minimum-add-to-make-parentheses-valid Medium
Array, Dynamic Programming, Greedy,
412 Sorting https://leetcode.com/problems/maximum-length-of-pair-chain Medium
Depth-First Search, Breadth-First
413 Search, Union Find, Graph https://leetcode.com/problems/possible-bipartition Medium
Array, Hash Table, Greedy, Heap
414 (Priority Queue) https://leetcode.com/problems/split-array-into-consecutive-subsequences Medium
Array, Depth-First Search, Breadth-
415 First Search, Union Find, Matrix https://leetcode.com/problems/making-a-large-island Hard
416 Array, Breadth-First Search, Matrix https://leetcode.com/problems/shortest-path-in-binary-matrix Medium
Tree, Depth-First Search, Breadth-First
417 Search, Binary Tree https://leetcode.com/problems/count-good-nodes-in-binary-tree Medium
418 Array https://leetcode.com/problems/shuffle-the-array Easy
Array, Hash Table, Sliding Window,
419 Heap (Priority Queue) https://leetcode.com/problems/sliding-window-median Hard
420 Array, Binary Search https://leetcode.com/problems/kth-missing-positive-number Easy
421 Array, Binary Search https://leetcode.com/problems/peak-index-in-a-mountain-array Easy
Array, Linked List, Stack, Monotonic
422 Stack https://leetcode.com/problems/next-greater-node-in-linked-list Medium
423 Array, Dynamic Programming https://leetcode.com/problems/minimum-swaps-to-make-sequences-increasing Hard
Array, Divide and Conquer, Sorting,
424 Quickselect https://leetcode.com/problems/wiggle-sort-ii Medium
Array, Hash Table, Greedy, Sliding
Window, Sorting, Heap (Priority
425 Queue) https://leetcode.com/problems/smallest-range-covering-elements-from-k-lists Hard
426 Math, String, Recursion https://leetcode.com/problems/integer-to-english-words Hard
427 Array, Dynamic Programming https://leetcode.com/problems/partition-array-for-maximum-sum Medium
428 Array, Sorting, Bucket Sort, Radix Sort https://leetcode.com/problems/maximum-gap Hard
Tree, Depth-First Search, Binary
429 Search Tree, Binary Tree https://leetcode.com/problems/find-mode-in-binary-search-tree Easy
Array, Hash Table, Binary Search,
430 Dynamic Programming https://leetcode.com/problems/longest-arithmetic-subsequence Medium
431 Array, Dynamic Programming https://leetcode.com/problems/last-stone-weight-ii Medium
432 Array, Heap (Priority Queue) https://leetcode.com/problems/last-stone-weight Easy
Tree, Depth-First Search, Breadth-First
433 Search, Binary Tree https://leetcode.com/problems/find-bottom-left-tree-value Medium
Depth-First Search, Breadth-First
434 Search, Union Find, Graph https://leetcode.com/problems/regions-cut-by-slashes Medium
Array, Dynamic Programming,
Backtracking, Bit Manipulation,
435 Bitmask https://leetcode.com/problems/beautiful-arrangement Medium
436 Array, Dynamic Programming, Matrix https://leetcode.com/problems/minimum-falling-path-sum Medium
437 Array, Matrix, Simulation https://leetcode.com/problems/diagonal-traverse Medium
Array, Queue, Sliding Window, Heap
(Priority Queue), Ordered Set,
438 Monotonic Queue https://leetcode.com/problems/longest-continuous-subarray-with-absolute-diff-less-than-or-equal-to-limit
Medium
439 Bit Manipulation https://leetcode.com/problems/number-complement Easy
440 Math, Binary Search https://leetcode.com/problems/valid-perfect-square Easy
441 Math, Binary Search https://leetcode.com/problems/arranging-coins Easy
442 Math, Two Pointers, String https://leetcode.com/problems/next-greater-element-iii Medium
Array, Binary Search, Depth-First
Search, Breadth-First Search, Union
443 Find, Heap (Priority Queue), Matrix https://leetcode.com/problems/path-with-minimum-effort Medium
444 Array, String, Trie https://leetcode.com/problems/search-suggestions-system Medium
 Array, Two Pointers, Matrix,
445 Simulation https://leetcode.com/problems/flipping-an-image Easy
Tree, Design, Binary Search Tree,
Heap (Priority Queue), Binary Tree,
446 Data Stream https://leetcode.com/problems/kth-largest-element-in-a-stream Easy
Array, Binary Search, Dynamic
447 Programming, Matrix, Ordered Set https://leetcode.com/problems/max-sum-of-rectangle-no-larger-than-k Hard
Hash Table, String, Binary Search,
448 Design https://leetcode.com/problems/time-based-key-value-store Medium
449 Linked List, Sorting https://leetcode.com/problems/insertion-sort-list Medium
450 Two Pointers, String https://leetcode.com/problems/string-compression Medium
Tree, Depth-First Search, Breadth-First
451 Search https://leetcode.com/problems/maximum-depth-of-n-ary-tree Easy
452 Math https://leetcode.com/problems/factorial-trailing-zeroes Medium
Array, Sorting, Heap (Priority Queue),
453 Simulation, Prefix Sum https://leetcode.com/problems/car-pooling Medium
Tree, Depth-First Search, Breadth-First
454 Search, Binary Tree https://leetcode.com/problems/find-largest-value-in-each-tree-row Medium
455 String, Dynamic Programming https://leetcode.com/problems/shortest-common-supersequence Hard
456 Dynamic Programming https://leetcode.com/problems/number-of-dice-rolls-with-target-sum Medium
Hash Table, Linked List, Design, Heap
457 (Priority Queue) https://leetcode.com/problems/design-twitter Medium
458 Array, Depth-First Search https://leetcode.com/problems/array-nesting Medium
Array, Math, Dynamic Programming,
459 Game Theory https://leetcode.com/problems/stone-game Medium
460 Array, Hash Table https://leetcode.com/problems/degree-of-an-array Easy
Hash Table, String, Bit Manipulation,
461 Sorting https://leetcode.com/problems/find-the-difference Easy
Tree, Depth-First Search, Breadth-First
Search, Binary Search Tree, Binary
462 Tree https://leetcode.com/problems/minimum-absolute-difference-in-bst Easy
463 Array, Binary Search, Matrix https://leetcode.com/problems/count-negative-numbers-in-a-sorted-matrix Easy
464 Array, Greedy, Heap (Priority Queue) https://leetcode.com/problems/course-schedule-iii Hard
Hash Table, Tree, Depth-First Search,
465 Breadth-First Search, Binary Tree https://leetcode.com/problems/smallest-subtree-with-all-the-deepest-nodes Medium
466 Array, Matrix, Simulation https://leetcode.com/problems/reshape-the-matrix Easy
467 Array, Matrix https://leetcode.com/problems/toeplitz-matrix Easy
468 Dynamic Programming https://leetcode.com/problems/knight-probability-in-chessboard Medium
Array, Two Pointers, Binary Search,
469 Sorting https://leetcode.com/problems/find-k-th-smallest-pair-distance Hard
470 Design, Segment Tree, Ordered Set https://leetcode.com/problems/my-calendar-i Medium
471 String, Dynamic Programming https://leetcode.com/problems/minimum-ascii-delete-sum-for-two-strings Medium
472 Array, Breadth-First Search, Matrix https://leetcode.com/problems/shortest-path-in-a-grid-with-obstacles-eliminationHard
473 Array, Design, Prefix Sum https://leetcode.com/problems/range-sum-query-immutable Easy
Tree, Breadth-First Search, Binary
474 Tree https://leetcode.com/problems/check-completeness-of-a-binary-tree Medium
475 Array https://leetcode.com/problems/maximize-distance-to-closest-person Medium
476 Stack, Design, Queue https://leetcode.com/problems/implement-stack-using-queues Easy
Math, Dynamic Programming, Bit
Manipulation, Memoization, Game
477 Theory, Bitmask https://leetcode.com/problems/can-i-win Medium
478 Hash Table, String, Sorting https://leetcode.com/problems/custom-sort-string Medium
479 Array, Hash Table https://leetcode.com/problems/brick-wall Medium
Array, Hash Table, Stack, Monotonic
480 Stack https://leetcode.com/problems/next-greater-element-i Easy
481 Tree, Depth-First Search, Binary Tree https://leetcode.com/problems/sum-of-root-to-leaf-binary-numbers Easy
Depth-First Search, Breadth-First
482 Search, Graph, Topological Sort https://leetcode.com/problems/find-eventual-safe-states Medium
483 Array, Queue, Sorting, Simulation https://leetcode.com/problems/reveal-cards-in-increasing-order Medium
Array, String, Dynamic Programming,
484 Depth-First Search, Trie https://leetcode.com/problems/concatenated-words Hard
485 Array, Two Pointers, Greedy, Sorting https://leetcode.com/problems/boats-to-save-people Medium
Array, Hash Table, Divide and
486 Conquer, Tree, Binary Tree https://leetcode.com/problems/construct-binary-tree-from-preorder-and-postorder-traversal
Medium
Array, Dynamic Programming, Binary
487 Indexed Tree https://leetcode.com/problems/count-number-of-teams Medium
Hash Table, String, Bit Manipulation,
Sliding Window, Rolling Hash, Hash
488 Function https://leetcode.com/problems/repeated-dna-sequences Medium
489 Hash Table, String, Sliding Window https://leetcode.com/problems/substring-with-concatenation-of-all-words Hard
Array, Hash Table, Breadth-First
490 Search https://leetcode.com/problems/bus-routes Hard
491 Array, Hash Table, String https://leetcode.com/problems/find-and-replace-pattern Medium
Array, Binary Search, Depth-First
Search, Breadth-First Search, Union
492 Find, Heap (Priority Queue), Matrix https://leetcode.com/problems/swim-in-rising-water Hard
 Depth-First Search, Breadth-First
493 Search, Union Find, Graph https://leetcode.com/problems/number-of-operations-to-make-network-connected
Medium
Array, Divide and Conquer, Sorting,
Heap (Priority Queue), Merge Sort,
494 Bucket Sort, Radix Sort, Counting Sort https://leetcode.com/problems/sort-an-array Medium
495 Array, Backtracking, Matrix https://leetcode.com/problems/path-with-maximum-gold Medium
Array, Hash Table, Bit Manipulation,
496 Sorting https://leetcode.com/problems/set-mismatch Easy
497 Linked List https://leetcode.com/problems/split-linked-list-in-parts Medium
Array, Two Pointers, Dynamic
498 Programming, Enumeration https://leetcode.com/problems/longest-mountain-in-array Medium
499 String, String Matching https://leetcode.com/problems/rotate-string Easy
500 Array, Hash Table, String https://leetcode.com/problems/unique-email-addresses Easy
 Crack The Coding Interview - Dinesh Varyani
https://www.youtube.com/user/hubberspot?sub_confirmation=1

# Topic Question Difficulty

501 Array, String, Bit Manipulation https://leetcode.com/problems/maximum-product-of-word-lengths Medium

Array, Stack, Greedy, Sorting,
502 Monotonic Stack https://leetcode.com/problems/max-chunks-to-make-sorted Medium
503 String, Dynamic Programming https://leetcode.com/problems/flip-string-to-monotone-increasing Medium
504 Array, Two Pointers, Sorting https://leetcode.com/problems/sort-array-by-parity-ii Easy
Array, String, Backtracking, Bit
505 Manipulation https://leetcode.com/problems/maximum-length-of-a-concatenated-string-with-unique-characters
Medium
506 Tree, Breadth-First Search https://leetcode.com/problems/n-ary-tree-level-order-traversal Medium
Array, Hash Table, Two Pointers,
507 Binary Search, Sorting https://leetcode.com/problems/k-diff-pairs-in-an-array Medium
508 String, Stack, Tree, Binary Tree https://leetcode.com/problems/verify-preorder-serialization-of-a-binary-tree Medium
509 String, Simulation https://leetcode.com/problems/robot-return-to-origin Easy
510 Dynamic Programming https://leetcode.com/problems/count-sorted-vowel-strings Medium
511 Array, Greedy https://leetcode.com/problems/minimum-domino-rotations-for-equal-row Medium
512 Array https://leetcode.com/problems/longest-continuous-increasing-subsequence Easy
String, Binary Search, Sliding Window,
Rolling Hash, Suffix Array, Hash
513 Function https://leetcode.com/problems/longest-duplicate-substring Hard
514 String, Greedy, Counting https://leetcode.com/problems/split-a-string-in-balanced-strings Easy
515 Math, Simulation, Number Theory https://leetcode.com/problems/add-digits Easy
516 Array, Greedy, Matrix https://leetcode.com/problems/max-increase-to-keep-city-skyline Medium
Array, Math, Two Pointers, String,
517 Greedy https://leetcode.com/problems/di-string-match Easy
Two Pointers, String, Dynamic
518 Programming https://leetcode.com/problems/push-dominoes Medium
519 Tree, Depth-First Search, Binary Tree https://leetcode.com/problems/leaf-similar-trees Easy
520 Array, Dynamic Programming https://leetcode.com/problems/maximum-sum-of-3-non-overlapping-subarrays Hard
521 Array, String, Simulation https://leetcode.com/problems/text-justification Hard
522 Array, Math, Prefix Sum https://leetcode.com/problems/sum-of-all-odd-length-subarrays Easy
523 Binary Search https://leetcode.com/problems/kth-smallest-number-in-multiplication-table Hard
Array, Greedy, Sorting, Heap (Priority
524 Queue) https://leetcode.com/problems/minimum-cost-to-hire-k-workers Hard
525 Array, Greedy, Heap (Priority Queue) https://leetcode.com/problems/maximum-number-of-events-that-can-be-attendedMedium
526 Array, Dynamic Programming https://leetcode.com/problems/uncrossed-lines Medium
527 Array, String, Sorting https://leetcode.com/problems/reorder-data-in-log-files Easy
Tree, Depth-First Search, Breadth-First
528 Search, Binary Tree https://leetcode.com/problems/sum-of-nodes-with-even-valued-grandparent Medium
529 Array, Math, Bit Manipulation https://leetcode.com/problems/total-hamming-distance Medium
Array, Hash Table, Sorting, Counting
530 Sort https://leetcode.com/problems/relative-sort-array Easy
531 Tree, Depth-First Search, Binary Tree https://leetcode.com/problems/binary-tree-tilt Easy
Array, Dynamic Programming, Sliding
532 Window https://leetcode.com/problems/maximum-sum-of-two-non-overlapping-subarraysMedium
Array, Hash Table, Math, Design,
533 Randomized https://leetcode.com/problems/insert-delete-getrandom-o1-duplicates-allowed Hard
Greedy, Depth-First Search, Breadth-
534 First Search, Union Find, Graph https://leetcode.com/problems/couples-holding-hands Hard
535 Stack, Tree, Depth-First Search https://leetcode.com/problems/n-ary-tree-preorder-traversal Easy
536 String, Backtracking https://leetcode.com/problems/letter-tile-possibilities Medium
537 Array, Linked List, Design, Queue https://leetcode.com/problems/design-circular-queue Medium
538 Array, Two Pointers https://leetcode.com/problems/number-of-subarrays-with-bounded-maximum Medium
539 Array, Matrix, Prefix Sum https://leetcode.com/problems/matrix-block-sum Medium
540 Array, Dynamic Programming https://leetcode.com/problems/largest-sum-of-averages Medium
541 Tree, Depth-First Search, Binary Tree https://leetcode.com/problems/flip-equivalent-binary-trees Medium
542 Array, Hash Table, Matrix, Prefix Sum https://leetcode.com/problems/number-of-submatrices-that-sum-to-target Hard
Array, Dynamic Programming,
Backtracking, Bit Manipulation,
543 Bitmask https://leetcode.com/problems/matchsticks-to-square Medium
Divide and Conquer, Greedy, Tree,
Depth-First Search, Binary Search
544 Tree, Binary Tree https://leetcode.com/problems/balance-a-binary-search-tree Medium
545 Array, Stack https://leetcode.com/problems/exclusive-time-of-functions Medium
546 Array, Sorting https://leetcode.com/problems/third-maximum-number Easy
547 Hash Table, Math, String https://leetcode.com/problems/fraction-to-recurring-decimal Medium
Array, String, Design, Trie, Data
548 Stream https://leetcode.com/problems/stream-of-characters Hard
Depth-First Search, Breadth-First
549 Search, Union Find, Graph https://leetcode.com/problems/redundant-connection-ii Hard
 Tree, Depth-First Search, Breadth-First
Search, Binary Search Tree, Binary
550 Tree https://leetcode.com/problems/minimum-distance-between-bst-nodes Easy
551 Backtracking https://leetcode.com/problems/n-queens-ii Hard
552 Array, Hash Table, Sorting https://leetcode.com/problems/longest-harmonious-subsequence Easy
Hash Table, Depth-First Search,
553 Breadth-First Search https://leetcode.com/problems/employee-importance Medium
554 Two Pointers, String https://leetcode.com/problems/long-pressed-name Easy
555 Array, Sorting, Matrix https://leetcode.com/problems/sort-the-matrix-diagonally Medium
556 Array, Two Pointers https://leetcode.com/problems/duplicate-zeros Easy
Array, Hash Table, Math, Sliding
557 Window https://leetcode.com/problems/count-number-of-nice-subarrays Medium
558 Hash Table, String, Counting https://leetcode.com/problems/ransom-note Easy
559 Math, Bit Manipulation, Recursion https://leetcode.com/problems/k-th-symbol-in-grammar Medium
Array, Dynamic Programming,
560 Memoization https://leetcode.com/problems/remove-boxes Hard
561 Stack, Tree, Depth-First Search https://leetcode.com/problems/n-ary-tree-postorder-traversal Easy
562 Array, Dynamic Programming https://leetcode.com/problems/minimum-cost-to-merge-stones Hard
563 Array, Greedy, Heap (Priority Queue) https://leetcode.com/problems/furthest-building-you-can-reach Medium
Array, Binary Search, Divide and
Conquer, Binary Indexed Tree,
Segment Tree, Merge Sort, Ordered
564 Set https://leetcode.com/problems/count-of-range-sum Hard
Array, Depth-First Search, Breadth-
565 First Search, Union Find, Matrix https://leetcode.com/problems/number-of-closed-islands Medium
566 Two Pointers, String https://leetcode.com/problems/reverse-vowels-of-a-string Easy
567 Dynamic Programming https://leetcode.com/problems/out-of-boundary-paths Medium
Tree, Depth-First Search, Binary
568 Search Tree, Sorting, Binary Tree https://leetcode.com/problems/all-elements-in-two-binary-search-trees Medium
569 String, Dynamic Programming https://leetcode.com/problems/minimum-insertion-steps-to-make-a-string-palindrome
Hard
570 Array, Sliding Window https://leetcode.com/problems/maximum-average-subarray-i Easy
571 Math, Bit Manipulation https://leetcode.com/problems/number-of-steps-to-reduce-a-number-to-zero Easy
Math, Dynamic Programming,
572 Memoization https://leetcode.com/problems/n-th-tribonacci-number Easy
Array, Binary Search, Sorting, Heap
573 (Priority Queue), Matrix https://leetcode.com/problems/the-k-weakest-rows-in-a-matrix Easy
574 Array https://leetcode.com/problems/valid-mountain-array Easy
575 Array, Binary Search https://leetcode.com/problems/minimum-number-of-days-to-make-m-bouquets Medium
Array, Hash Table, Binary Search,
576 Sliding Window, Prefix Sum https://leetcode.com/problems/minimum-operations-to-reduce-x-to-zero Medium
Array, Dynamic Programming, Stack,
577 Matrix, Monotonic Stack https://leetcode.com/problems/count-submatrices-with-all-ones Medium
Math, Dynamic Programming, Game
578 Theory https://leetcode.com/problems/guess-number-higher-or-lower-ii Medium
Array, Dynamic Programming,
579 Breadth-First Search, Matrix https://leetcode.com/problems/as-far-from-land-as-possible Medium
Tree, Depth-First Search, Breadth-First
580 Search https://leetcode.com/problems/time-needed-to-inform-all-employees Medium
String, Stack, Greedy, Monotonic
581 Stack https://leetcode.com/problems/smallest-subsequence-of-distinct-characters Medium
582 Array, Hash Table, String, Trie https://leetcode.com/problems/replace-words Medium
583 Array, Breadth-First Search, Matrix https://leetcode.com/problems/sliding-puzzle Hard
584 Two Pointers, String https://leetcode.com/problems/reverse-only-letters Easy
Array, Hash Table, Backtracking, Bit
585 Manipulation https://leetcode.com/problems/increasing-subsequences Medium
586 Array https://leetcode.com/problems/monotonic-array Easy
Array, Hash Table, Binary Search,
587 Design https://leetcode.com/problems/snapshot-array Medium
588 Array, Sorting https://leetcode.com/problems/minimum-absolute-difference Easy
589 Array https://leetcode.com/problems/summary-ranges Easy
590 Dynamic Programming https://leetcode.com/problems/domino-and-tromino-tiling Medium
Array, Hash Table, Dynamic
591 Programming https://leetcode.com/problems/length-of-longest-fibonacci-subsequence Medium
592 Linked List, Two Pointers https://leetcode.com/problems/swapping-nodes-in-a-linked-list Medium
593 Math, Backtracking, Bit Manipulation https://leetcode.com/problems/gray-code Medium
Array, Hash Table, Math, Geometry,
594 Sorting https://leetcode.com/problems/minimum-area-rectangle Medium
595 Array, Depth-First Search, Matrix https://leetcode.com/problems/battleships-in-a-board Medium
Hash Table, Tree, Depth-First Search,
596 Binary Tree https://leetcode.com/problems/most-frequent-subtree-sum Medium
597 Array, Math, Greedy https://leetcode.com/problems/minimum-cost-to-move-chips-to-the-same-position
Easy
598 Math, Geometry https://leetcode.com/problems/rectangle-overlap Easy
Array, Hash Table, Math, Dynamic
599 Programming, Heap (Priority Queue) https://leetcode.com/problems/super-ugly-number Medium
600 Hash Table, String https://leetcode.com/problems/buddy-strings Easy
601 Array, Dynamic Programming, Greedy https://leetcode.com/problems/minimum-number-of-taps-to-open-to-water-a-garden
Hard
602 Array https://leetcode.com/problems/kids-with-the-greatest-number-of-candies Easy
603 String, String Matching https://leetcode.com/problems/repeated-string-match Medium
604 Array, String, Union Find, Graph https://leetcode.com/problems/satisfiability-of-equality-equations Medium
Hash Table, String, Depth-First Search,
605 Breadth-First Search, Union Find https://leetcode.com/problems/smallest-string-with-swaps Medium
Dynamic Programming, Bit
Manipulation, Breadth-First Search,
606 Graph, Bitmask https://leetcode.com/problems/shortest-path-visiting-all-nodes Hard
607 Array, Math https://leetcode.com/problems/minimum-moves-to-equal-array-elements Medium
608 Dynamic Programming https://leetcode.com/problems/knight-dialer Medium
609 Hash Table, Linked List https://leetcode.com/problems/remove-zero-sum-consecutive-nodes-from-linked-list
Medium
610 Array, Dynamic Programming https://leetcode.com/problems/best-sightseeing-pair Medium
611 Math, Bit Manipulation, Recursion https://leetcode.com/problems/power-of-four Easy
612 Array, Two Pointers, String, Sorting https://leetcode.com/problems/longest-word-in-dictionary-through-deleting Medium
613 Array, Greedy, Sorting https://leetcode.com/problems/maximum-units-on-a-truck Easy
String, Tree, Depth-First Search,
614 Binary Tree https://leetcode.com/problems/construct-string-from-binary-tree Easy
615 Array, Greedy, Sorting https://leetcode.com/problems/assign-cookies Easy
616 String, Dynamic Programming https://leetcode.com/problems/scramble-string Hard
617 Array, Hash Table, Math, Prefix Sum https://leetcode.com/problems/continuous-subarray-sum Medium
Array, Depth-First Search, Breadth-
618 First Search, Matrix https://leetcode.com/problems/minesweeper Medium
619 Hash Table, String, Counting https://leetcode.com/problems/bulls-and-cows Medium
620 Linked List, Design https://leetcode.com/problems/design-linked-list Medium
621 Array, Hash Table, Greedy, Sorting https://leetcode.com/problems/hand-of-straights Medium
Array, Dynamic Programming, Stack,
622 Monotonic Stack, Ordered Set https://leetcode.com/problems/odd-even-jump Hard
623 Array, Dynamic Programming https://leetcode.com/problems/arithmetic-slices-ii-subsequence Hard
624 Array, Math, Sorting https://leetcode.com/problems/minimum-moves-to-equal-array-elements-ii Medium
Tree, Breadth-First Search, Binary
625 Tree https://leetcode.com/problems/maximum-level-sum-of-a-binary-tree Medium
626 Stack, Greedy, Monotonic Stack https://leetcode.com/problems/create-maximum-number Hard
Hash Table, Tree, Depth-First Search,
627 Breadth-First Search, Binary Tree https://leetcode.com/problems/delete-leaves-with-a-given-value Medium
628 Array, Binary Search https://leetcode.com/problems/find-smallest-letter-greater-than-target Easy
629 Array, Hash Table, String, Trie, Sorting https://leetcode.com/problems/longest-word-in-dictionary Medium
Array, Two Pointers, Binary Search,
630 Sorting https://leetcode.com/problems/heaters Medium
631 Array, Math, Union Find https://leetcode.com/problems/largest-component-size-by-common-factor Hard
Linked List, Tree, Depth-First Search,
632 Breadth-First Search, Binary Tree https://leetcode.com/problems/linked-list-in-binary-tree Medium
Depth-First Search, Breadth-First
633 Search, Graph https://leetcode.com/problems/reorder-routes-to-make-all-paths-lead-to-the-city-zero
Medium
634 Math, Two Pointers, Binary Search https://leetcode.com/problems/sum-of-square-numbers Medium
635 Hash Table, String, Sliding Window https://leetcode.com/problems/number-of-substrings-containing-all-three-characters
Medium
636 Hash Table, String https://leetcode.com/problems/most-common-word Easy
637 Array, Greedy, Sorting https://leetcode.com/problems/advantage-shuffle Medium
Array, Hash Table, Math, Bit
638 Manipulation https://leetcode.com/problems/prison-cells-after-n-days Medium
Array, Dynamic Programming, Sliding
639 Window https://leetcode.com/problems/longest-turbulent-subarray Medium
Tree, Depth-First Search, Breadth-First
640 Search, Binary Tree https://leetcode.com/problems/add-one-row-to-tree Medium
641 String, Dynamic Programming https://leetcode.com/problems/count-different-palindromic-subsequences Hard
642 Array, Binary Search https://leetcode.com/problems/find-the-smallest-divisor-given-a-threshold Medium
643 Math https://leetcode.com/problems/ugly-number Easy
Array, Math, Dynamic Programming,
644 Game Theory https://leetcode.com/problems/stone-game-ii Medium
645 Array, Stack, Sorting, Monotonic Stack https://leetcode.com/problems/car-fleet Medium
Array, Hash Table, Sliding Window,
646 Prefix Sum https://leetcode.com/problems/binary-subarrays-with-sum Medium
647 String https://leetcode.com/problems/consecutive-characters Easy
648 String, Stack https://leetcode.com/problems/simplify-path Medium
649 Array, Dynamic Programming https://leetcode.com/problems/filling-bookcase-shelves Medium
Tree, Depth-First Search, Breadth-First
650 Search, Binary Tree https://leetcode.com/problems/univalued-binary-tree Easy
Math, Dynamic Programming,
651 Brainteaser, Game Theory https://leetcode.com/problems/divisor-game Easy
Array, Math, String, Interactive, Game
652 Theory https://leetcode.com/problems/guess-the-word Hard
653 Array, Hash Table, String https://leetcode.com/problems/unique-morse-code-words Easy
 String, Dynamic Programming, Bit
654 Manipulation https://leetcode.com/problems/number-of-good-ways-to-split-a-string Medium
655 String, Stack https://leetcode.com/problems/remove-outermost-parentheses Easy
656 Array, Math, Backtracking https://leetcode.com/problems/24-game Hard
657 Graph https://leetcode.com/problems/minimum-number-of-vertices-to-reach-all-nodes Medium
Array, Dynamic Programming, Queue,
Sliding Window, Heap (Priority Queue),
658 Monotonic Queue https://leetcode.com/problems/jump-game-vi Medium
659 Math, String https://leetcode.com/problems/greatest-common-divisor-of-strings Easy
660 Array, Dynamic Programming https://leetcode.com/problems/maximum-subarray-sum-with-one-deletion Medium
661 Tree, Depth-First Search, Binary Tree https://leetcode.com/problems/maximum-product-of-splitted-binary-tree Medium
Linked List, Math, Reservoir Sampling,
662 Randomized https://leetcode.com/problems/linked-list-random-node Medium
663 Hash Table, String, Design, Trie https://leetcode.com/problems/map-sum-pairs Medium
Array, Hash Table, Math, Counting,
664 Number Theory https://leetcode.com/problems/x-of-a-kind-in-a-deck-of-cards Easy
665 Array, Sorting, Counting Sort https://leetcode.com/problems/h-index Medium
666 Array, Hash Table https://leetcode.com/problems/unique-number-of-occurrences Easy
667 String, Stack https://leetcode.com/problems/reverse-substrings-between-each-pair-of-parentheses
Medium
668 String, Stack https://leetcode.com/problems/decoded-string-at-index Medium
669 Array, String https://leetcode.com/problems/minimum-number-of-operations-to-move-all-balls-to-each-box
Medium
670 Array https://leetcode.com/problems/partition-array-into-disjoint-intervals Medium
671 Array, String https://leetcode.com/problems/shuffle-string Easy
Hash Table, String, Design, Hash
672 Function https://leetcode.com/problems/encode-and-decode-tinyurl Medium
673 Array, Stack, Greedy, Monotonic Stack https://leetcode.com/problems/find-the-most-competitive-subsequence Medium
674 Array, Math, Geometry https://leetcode.com/problems/minimum-time-visiting-all-points Easy
675 String, Backtracking, Design, Iterator https://leetcode.com/problems/iterator-for-combination Medium
Array, Hash Table, Binary Search,
676 Sorting https://leetcode.com/problems/fair-candy-swap Easy
Array, Hash Table, Linked List, Design,
677 Hash Function https://leetcode.com/problems/design-hashset Easy
678 Array, Greedy https://leetcode.com/problems/lemonade-change Easy
679 Array, Math https://leetcode.com/problems/global-and-local-inversions Medium
Array, Hash Table, Greedy, Sorting,
680 Heap (Priority Queue) https://leetcode.com/problems/reduce-array-size-to-the-half Medium
681 Array, Dynamic Programming, Greedy https://leetcode.com/problems/video-stitching Medium
682 Tree, Depth-First Search, Binary Tree https://leetcode.com/problems/second-minimum-node-in-a-binary-tree Easy
Array, Greedy, Sorting, Heap (Priority
683 Queue) https://leetcode.com/problems/maximum-performance-of-a-team Hard
Array, Hash Table, Binary Search,
Dynamic Programming, Sliding
684 Window https://leetcode.com/problems/find-two-non-overlapping-sub-arrays-each-with-target-sum
Medium
685 Array https://leetcode.com/problems/replace-elements-with-greatest-element-on-right-side
Easy
686 String https://leetcode.com/problems/count-and-say Medium
687 Hash Table, String, Design https://leetcode.com/problems/design-underground-system Medium
688 Depth-First Search, Trie https://leetcode.com/problems/lexicographical-numbers Medium
689 Math https://leetcode.com/problems/self-dividing-numbers Easy
690 Array, Dynamic Programming, Greedy https://leetcode.com/problems/greatest-sum-divisible-by-three Medium
691 Array, Greedy https://leetcode.com/problems/patching-array Hard
692 Array, Dynamic Programming, Matrix https://leetcode.com/problems/cherry-pickup-ii Hard
693 Array, Hash Table, String https://leetcode.com/problems/minimum-index-sum-of-two-lists Easy
694 Design, Segment Tree, Ordered Set https://leetcode.com/problems/my-calendar-ii Medium
695 Array, Dynamic Programming https://leetcode.com/problems/largest-plus-sign Medium
696 Math, Greedy https://leetcode.com/problems/broken-calculator Medium
697 Array, Binary Search, Sorting https://leetcode.com/problems/find-right-interval Medium
698 Two Pointers, String https://leetcode.com/problems/compare-version-numbers Medium
699 Array, Dynamic Programming https://leetcode.com/problems/minimum-difficulty-of-a-job-schedule Hard
Array, Math, Binary Search, Dynamic
700 Programming https://leetcode.com/problems/numbers-at-most-n-given-digit-set Hard
701 Array, Stack, Monotonic Stack https://leetcode.com/problems/maximum-width-ramp Medium
Array, Hash Table, String, Bit
702 Manipulation, Trie https://leetcode.com/problems/number-of-valid-words-for-each-puzzle Hard
703 Array https://leetcode.com/problems/find-numbers-with-even-number-of-digits Easy
704 Array, Sliding Window https://leetcode.com/problems/grumpy-bookstore-owner Medium
705 Array, Hash Table, Sorting https://leetcode.com/problems/sort-array-by-increasing-frequency Easy
706 Array, Matrix https://leetcode.com/problems/richest-customer-wealth Easy
707 Dynamic Programming https://leetcode.com/problems/non-negative-integers-without-consecutive-ones Hard
Hash Table, Tree, Depth-First Search,
708 Breadth-First Search, Binary Tree https://leetcode.com/problems/lowest-common-ancestor-of-deepest-leaves Medium
709 Dynamic Programming https://leetcode.com/problems/student-attendance-record-ii Hard
710 Breadth-First Search, Graph https://leetcode.com/problems/shortest-path-with-alternating-colors Medium
711 Array, Two Pointers, Greedy, Sorting https://leetcode.com/problems/pancake-sorting Medium
712 Array, Dynamic Programming https://leetcode.com/problems/maximum-number-of-points-with-cost Medium
713 String, Dynamic Programming https://leetcode.com/problems/unique-substrings-in-wraparound-string Medium
714 String, Greedy, Sorting https://leetcode.com/problems/minimum-deletions-to-make-character-frequencies-unique
Medium
715 Hash Table, String https://leetcode.com/problems/minimum-number-of-steps-to-make-two-strings-anagram
Medium
Hash Table, Linked List, Design,
716 Doubly-Linked List https://leetcode.com/problems/all-oone-data-structure Hard
717 String https://leetcode.com/problems/detect-capital Easy
Hash Table, String, Bit Manipulation,
718 Prefix Sum https://leetcode.com/problems/find-the-longest-substring-containing-vowels-in-even-counts
Medium
719 Array, Matrix, Simulation https://leetcode.com/problems/transpose-matrix Easy
720 Array, Greedy https://leetcode.com/problems/partition-array-into-three-parts-with-equal-sum Easy
721 Array, Hash Table, Greedy, Sorting https://leetcode.com/problems/divide-array-in-sets-of-k-consecutive-numbers Medium
722 Array, Math, Greedy, Sorting https://leetcode.com/problems/smallest-range-ii Medium
723 Math, Binary Search https://leetcode.com/problems/reach-a-number Medium
Graph, Heap (Priority Queue), Shortest
724 Path https://leetcode.com/problems/path-with-maximum-probability Medium
725 Math, Brainteaser, Game Theory https://leetcode.com/problems/nim-game Easy
Array, Stack, Greedy, Sorting,
726 Monotonic Stack https://leetcode.com/problems/max-chunks-to-make-sorted-ii Hard
727 Array, Hash Table, Greedy, Sorting https://leetcode.com/problems/array-of-doubled-pairs Medium
728 String, Dynamic Programming https://leetcode.com/problems/decode-ways-ii Hard
729 Array, Math https://leetcode.com/problems/add-to-array-form-of-integer Easy
730 Dynamic Programming https://leetcode.com/problems/champagne-tower Medium
731 Array, Dynamic Programming, Greedy https://leetcode.com/problems/maximum-length-of-subarray-with-positive-product
Medium
732 String, Dynamic Programming https://leetcode.com/problems/distinct-subsequences-ii Hard
Dynamic Programming, Graph,
733 Shortest Path https://leetcode.com/problems/find-the-city-with-the-smallest-number-of-neighbors-at-a-threshold-distance
Medium
734 Array, Greedy, Sorting https://leetcode.com/problems/maximum-area-of-a-piece-of-cake-after-horizontal-and-vertical-cuts
Medium
735 Array, Hash Table, String, Counting https://leetcode.com/problems/subdomain-visit-count Medium
736 String https://leetcode.com/problems/defanging-an-ip-address Easy
Array, Linked List, Stack, Design,
737 Doubly-Linked List, Data Stream https://leetcode.com/problems/design-browser-history Medium
738 Array, Design, Iterator https://leetcode.com/problems/peeking-iterator Medium
739 String, Dynamic Programming https://leetcode.com/problems/count-unique-characters-of-all-substrings-of-a-given-string
Hard
740 Tree, Depth-First Search, Binary Tree https://leetcode.com/problems/number-of-good-leaf-nodes-pairs Medium
Array, String, Dynamic Programming,
741 Bit Manipulation, Bitmask https://leetcode.com/problems/find-the-shortest-superstring Hard
String, Tree, Depth-First Search,
742 Binary Tree https://leetcode.com/problems/smallest-string-starting-from-leaf Medium
743 String https://leetcode.com/problems/string-to-integer-atoi Medium
744 Hash Table, Math https://leetcode.com/problems/smallest-integer-divisible-by-k Medium
745 Array, Binary Search, Interactive https://leetcode.com/problems/find-in-mountain-array Hard
String, Tree, Depth-First Search,
746 Binary Tree https://leetcode.com/problems/recover-a-tree-from-preorder-traversal Hard
747 String, Design, Trie https://leetcode.com/problems/prefix-and-suffix-search Hard
748 Array, Stack, Design https://leetcode.com/problems/design-a-stack-with-increment-operation Medium
Array, Hash Table, Breadth-First
749 Search https://leetcode.com/problems/jump-game-iv Hard
750 Array, Greedy, Sorting, Counting https://leetcode.com/problems/minimum-increment-to-make-array-unique Medium
751 Array, Dynamic Programming https://leetcode.com/problems/minimum-cost-to-cut-a-stick Hard
752 Hash Table, String, Design, Trie https://leetcode.com/problems/implement-magic-dictionary Medium
753 Array, Greedy, Sorting https://leetcode.com/problems/minimum-difference-between-largest-and-smallest-value-in-three-moves
Medium
754 Array, Greedy, Bit Manipulation, Matrix https://leetcode.com/problems/score-after-flipping-matrix Medium
Array, Dynamic Programming,
Backtracking, Bit Manipulation,
755 Memoization, Bitmask https://leetcode.com/problems/shopping-offers Medium
756 Array, Prefix Sum https://leetcode.com/problems/minimum-value-to-get-positive-step-by-step-sum Easy
Array, Union Find, Minimum Spanning
757 Tree https://leetcode.com/problems/min-cost-to-connect-all-points Medium
758 Array, Binary Search, Sorting https://leetcode.com/problems/magnetic-force-between-two-balls Medium
759 Array, Stack, Simulation https://leetcode.com/problems/baseball-game Easy
760 Math, Binary Search https://leetcode.com/problems/nth-magical-number Hard
761 String https://leetcode.com/problems/to-lower-case Easy
762 Hash Table, String, Counting https://leetcode.com/problems/maximum-number-of-balloons Easy
763 Math, Enumeration https://leetcode.com/problems/consecutive-numbers-sum Hard
764 String, Stack, Depth-First Search https://leetcode.com/problems/longest-absolute-file-path Medium
Array, Two Pointers, Binary Search,
765 Sorting https://leetcode.com/problems/number-of-subsequences-that-satisfy-the-given-sum-condition
Medium
766 Array, Dynamic Programming https://leetcode.com/problems/minimum-score-triangulation-of-polygon Medium
 Dynamic Programming, Tree, Depth-
767 First Search, Binary Tree https://leetcode.com/problems/longest-zigzag-path-in-a-binary-tree Medium
768 Design, Ordered Set https://leetcode.com/problems/exam-room Medium
769 Array, Prefix Sum https://leetcode.com/problems/corporate-flight-bookings Medium
Array, Dynamic Programming, Bit
770 Manipulation https://leetcode.com/problems/bitwise-ors-of-subarrays Medium
Math, Dynamic Programming, Sliding
771 Window, Probability and Statistics https://leetcode.com/problems/new-21-game Medium
772 Array, Math https://leetcode.com/problems/find-n-unique-integers-sum-up-to-zero Easy
Array, Binary Search, Greedy, Sliding
773 Window, Sorting, Prefix Sum https://leetcode.com/problems/frequency-of-the-most-frequent-element Medium
774 Array, Hash Table, String https://leetcode.com/problems/word-subsets Medium
Array, Breadth-First Search, Graph,
Heap (Priority Queue), Matrix, Shortest
775 Path https://leetcode.com/problems/minimum-cost-to-make-at-least-one-valid-path-in-a-grid
Hard
776 Backtracking, Bit Manipulation https://leetcode.com/problems/binary-watch Easy
777 Array, Hash Table https://leetcode.com/problems/distribute-candies Easy
778 Math https://leetcode.com/problems/reaching-points Hard
779 Math, Tree, Binary Tree https://leetcode.com/problems/path-in-zigzag-labelled-binary-tree Medium
Bit Manipulation, Tree, Depth-First
Search, Breadth-First Search, Binary
780 Tree https://leetcode.com/problems/pseudo-palindromic-paths-in-a-binary-tree Medium
781 Tree, Depth-First Search, Binary Tree https://leetcode.com/problems/binary-tree-coloring-game Medium
782 Dynamic Programming https://leetcode.com/problems/count-vowels-permutation Hard
Array, Depth-First Search, Breadth-
783 First Search, Union Find, Matrix https://leetcode.com/problems/number-of-enclaves Medium
784 String, Greedy, Heap (Priority Queue) https://leetcode.com/problems/longest-happy-string Medium
785 Array, Hash Table https://leetcode.com/problems/group-the-people-given-the-group-size-they-belong-to
Medium
786 Array, Hash Table, String https://leetcode.com/problems/find-words-that-can-be-formed-by-characters Easy
787 Math, Greedy https://leetcode.com/problems/maximum-69-number Easy
Array, Hash Table, Two Pointers,
788 Sorting, Counting https://leetcode.com/problems/3sum-with-multiplicity Medium
Array, Hash Table, Stack, Monotonic
789 Stack, Prefix Sum https://leetcode.com/problems/longest-well-performing-interval Medium
Array, Hash Table, Binary Search,
790 Greedy, Heap (Priority Queue) https://leetcode.com/problems/avoid-flood-in-the-city Medium
Dynamic Programming, Tree, Depth-
First Search, Binary Search Tree,
791 Binary Tree https://leetcode.com/problems/maximum-sum-bst-in-binary-tree Hard
Array, Math, Dynamic Programming,
792 Game Theory https://leetcode.com/problems/stone-game-iii Hard
Hash Table, Math, Reservoir Sampling,
793 Randomized https://leetcode.com/problems/random-pick-index Medium
794 Design, Segment Tree, Ordered Set https://leetcode.com/problems/range-module Hard
Array, Two Pointers, Binary Search,
795 Stack, Monotonic Stack https://leetcode.com/problems/shortest-subarray-to-be-removed-to-make-array-sorted
Medium
796 Hash Table, String, Stack https://leetcode.com/problems/number-of-atoms Hard
797 Hash Table, String https://leetcode.com/problems/destination-city Easy
798 Array, Math, String, Sorting https://leetcode.com/problems/minimum-time-difference Medium
799 Math https://leetcode.com/problems/subtract-the-product-and-sum-of-digits-of-an-integer
Easy
800 Array, Simulation https://leetcode.com/problems/create-target-array-in-the-given-order Easy
801 Array, Stack, Monotonic Stack https://leetcode.com/problems/final-prices-with-a-special-discount-in-a-shop Easy
802 Array, Greedy, Sorting https://leetcode.com/problems/maximize-sum-of-array-after-k-negations Easy
Math, Rejection Sampling,
803 Randomized, Probability and Statistics https://leetcode.com/problems/implement-rand10-using-rand7 Medium
Hash Table, Tree, Depth-First Search,
804 Breadth-First Search https://leetcode.com/problems/minimum-time-to-collect-all-apples-in-a-tree Medium
Binary Search, Dynamic Programming,
Tree, Depth-First Search, Breadth-First
805 Search, Design https://leetcode.com/problems/kth-ancestor-of-a-tree-node Hard
Array, Breadth-First Search, Heap
806 (Priority Queue), Matrix https://leetcode.com/problems/cut-off-trees-for-golf-event Hard
807 Math, Brainteaser https://leetcode.com/problems/bulb-switcher Medium
808 Hash Table, String https://leetcode.com/problems/uncommon-words-from-two-sentences Easy
Array, String, Dynamic Programming,
809 Greedy https://leetcode.com/problems/minimum-time-to-make-rope-colorful Medium
810 Bit Manipulation https://leetcode.com/problems/binary-number-with-alternating-bits Easy
Array, Hash Table, Dynamic
811 Programming https://leetcode.com/problems/longest-arithmetic-subsequence-of-given-difference
Medium
812 Array, Matrix https://leetcode.com/problems/matrix-diagonal-sum Easy
813 Array, Sorting https://leetcode.com/problems/remove-covered-intervals Medium
814 Array, Hash Table, String https://leetcode.com/problems/keyboard-row Easy
815 Array, Hash Table https://leetcode.com/problems/n-repeated-element-in-size-2n-array Easy
816 Math https://leetcode.com/problems/angle-between-hands-of-a-clock Medium
817 Two Pointers, String https://leetcode.com/problems/reverse-string-ii Easy
818 Math, Bit Manipulation https://leetcode.com/problems/convert-a-number-to-hexadecimal Easy
819 Backtracking, Breadth-First Search https://leetcode.com/problems/numbers-with-same-consecutive-differences Medium
820 Array, String https://leetcode.com/problems/shifting-letters Medium
Array, Hash Table, Dynamic
821 Programming https://leetcode.com/problems/binary-trees-with-factors Medium
Array, Hash Table, Math, Bit
822 Manipulation, Prefix Sum https://leetcode.com/problems/count-triplets-that-can-form-two-arrays-of-equal-xor
Medium
Array, Bit Manipulation, Sorting,
823 Counting https://leetcode.com/problems/sort-integers-by-the-number-of-1-bits Easy
Math, Dynamic Programming,
824 Backtracking https://leetcode.com/problems/count-numbers-with-unique-digits Medium
825 Array, Bit Manipulation, Prefix Sum https://leetcode.com/problems/xor-queries-of-a-subarray Medium
826 Math, Greedy https://leetcode.com/problems/monotone-increasing-digits Medium
827 Dynamic Programming https://leetcode.com/problems/race-car Hard
828 String, Backtracking https://leetcode.com/problems/split-array-into-fibonacci-sequence Medium
Array, Math, Design, Queue, Data
829 Stream https://leetcode.com/problems/product-of-the-last-k-numbers Medium
830 Array, Dynamic Programming https://leetcode.com/problems/k-concatenation-maximum-sum Medium
Array, Depth-First Search, Breadth-
First Search, Union Find, Matrix,
831 Counting https://leetcode.com/problems/count-servers-that-communicate Medium
Array, Dynamic Programming, Greedy,
832 Sorting https://leetcode.com/problems/reducing-dishes Hard
833 Array, Math, Greedy, Sorting https://leetcode.com/problems/largest-perimeter-triangle Easy
834 Array, Matrix https://leetcode.com/problems/lucky-numbers-in-a-matrix Easy
835 Array, Hash Table, Prefix Sum https://leetcode.com/problems/make-sum-divisible-by-p Medium
836 Array, Hash Table, String https://leetcode.com/problems/find-duplicate-file-in-system Medium
837 Array, Hash Table, Sorting https://leetcode.com/problems/rank-transform-of-an-array Easy
838 Array, Math, Divide and Conquer https://leetcode.com/problems/beautiful-array Medium
839 String https://leetcode.com/problems/decrypt-string-from-alphabet-to-integer-mapping Easy
Array, Math, Recursion, Queue,
840 Simulation https://leetcode.com/problems/find-the-winner-of-the-circular-game Medium
841 Array, Binary Search https://leetcode.com/problems/minimum-limit-of-balls-in-a-bag Medium
842 Math, String, Greedy https://leetcode.com/problems/minimum-swaps-to-make-strings-equal Medium
843 String, Breadth-First Search https://leetcode.com/problems/k-similar-strings Hard
Array, Hash Table, Greedy, Sorting,
844 Heap (Priority Queue), Counting https://leetcode.com/problems/distant-barcodes Medium
845 Array, Greedy, Matrix https://leetcode.com/problems/find-valid-matrix-given-row-and-column-sums Medium
846 Array, Simulation https://leetcode.com/problems/build-array-from-permutation Easy
Array, Binary Search, Heap (Priority
847 Queue), Matrix https://leetcode.com/problems/find-the-kth-smallest-sum-of-a-matrix-with-sorted-rows
Hard
848 Array, Sorting, Heap (Priority Queue) https://leetcode.com/problems/maximum-product-of-two-elements-in-an-array Easy
Array, Segment Tree, Line Sweep,
849 Ordered Set https://leetcode.com/problems/rectangle-area-ii Hard
Depth-First Search, Breadth-First
850 Search, Graph https://leetcode.com/problems/flower-planting-with-no-adjacent Medium
851 Array, Sorting, Heap (Priority Queue) https://leetcode.com/problems/diagonal-traverse-ii Medium
Array, Math, Dynamic Programming,
852 Bit Manipulation, Bitmask https://leetcode.com/problems/split-array-with-same-average Hard
853 String, Dynamic Programming https://leetcode.com/problems/strange-printer Hard
Array, Dynamic Programming, Stack,
854 Greedy, Monotonic Stack https://leetcode.com/problems/minimum-number-of-increments-on-subarrays-to-form-a-target-array
Hard
855 Dynamic Programming https://leetcode.com/problems/k-inverse-pairs-array Hard
856 Hash Table, Math, Geometry https://leetcode.com/problems/max-points-on-a-line Hard
Dynamic Programming, Memoization,
857 Sorting https://leetcode.com/problems/sort-integers-by-the-power-value Medium
858 Array, Hash Table, Counting https://leetcode.com/problems/check-if-array-pairs-are-divisible-by-k Medium
859 Math, Dynamic Programming https://leetcode.com/problems/rotate-function Medium
Array, Queue, Sliding Window, Heap
860 (Priority Queue), Monotonic Queue https://leetcode.com/problems/max-value-of-equation Hard
Hash Table, String, Breadth-First
861 Search https://leetcode.com/problems/minimum-genetic-mutation Medium
862 Array, Union Find, Matrix https://leetcode.com/problems/bricks-falling-when-hit Hard
Array, Two Pointers, Binary Search,
863 Greedy, Sorting https://leetcode.com/problems/most-profit-assigning-work Medium
864 Array, Math, Geometry https://leetcode.com/problems/check-if-it-is-a-straight-line Easy
Dynamic Programming, Greedy, Bit
865 Manipulation, Memoization https://leetcode.com/problems/integer-replacement Medium
866 Array, Hash Table, Sliding Window https://leetcode.com/problems/maximum-erasure-value Medium
867 Linked List https://leetcode.com/problems/merge-in-between-linked-lists Medium
868 Bit Manipulation, Breadth-First Search https://leetcode.com/problems/shortest-path-to-get-all-keys Hard
869 String https://leetcode.com/problems/license-key-formatting Easy
 Math, Dynamic Programming, Sliding
870 Window https://leetcode.com/problems/longest-subarray-of-1s-after-deleting-one-elementMedium
Array, Hash Table, Greedy, Sorting,
871 Counting https://leetcode.com/problems/least-number-of-unique-integers-after-k-removalsMedium
872 Math https://leetcode.com/problems/elimination-game Medium
Array, Binary Search, Matrix, Prefix
873 Sum https://leetcode.com/problems/maximum-side-length-of-a-square-with-sum-less-than-or-equal-to-threshold
Medium
Array, Bit Manipulation, Sliding
874 Window, Prefix Sum https://leetcode.com/problems/minimum-number-of-k-consecutive-bit-flips Hard
875 String, Dynamic Programming https://leetcode.com/problems/minimum-distance-to-type-a-word-using-two-fingers
Hard
876 Dynamic Programming https://leetcode.com/problems/number-of-ways-to-paint-n-3-grid Hard
877 Design, Queue, Data Stream https://leetcode.com/problems/number-of-recent-calls Easy
878 Array, Dynamic Programming https://leetcode.com/problems/ways-to-make-a-fair-array Medium
879 Math, Geometry https://leetcode.com/problems/rectangle-area Medium
880 Math https://leetcode.com/problems/minimum-operations-to-make-array-equal Medium
881 Math, Bit Manipulation https://leetcode.com/problems/xor-operation-in-an-array Easy
String, Depth-First Search, Breadth-
882 First Search, Union Find https://leetcode.com/problems/similar-string-groups Hard
883 Array, Dynamic Programming, Sorting https://leetcode.com/problems/best-team-with-no-conflicts Medium
Array, Greedy, Sorting, Heap (Priority
884 Queue) https://leetcode.com/problems/ipo Hard
885 Array, Hash Table, Matrix, Simulation https://leetcode.com/problems/find-winner-on-a-tic-tac-toe-game Easy
Array, Dynamic Programming, Queue,
Sliding Window, Heap (Priority Queue),
886 Monotonic Queue https://leetcode.com/problems/constrained-subsequence-sum Hard
887 Bit Manipulation https://leetcode.com/problems/complement-of-base-10-integer Easy
Array, Binary Search, Heap (Priority
888 Queue) https://leetcode.com/problems/k-th-smallest-prime-fraction Hard
889 Two Pointers, String https://leetcode.com/problems/swap-adjacent-in-lr-string Medium
Array, Hash Table, String, Sorting,
890 Counting https://leetcode.com/problems/rank-teams-by-votes Medium
891 String, Sliding Window https://leetcode.com/problems/replace-the-substring-for-balanced-string Medium
892 String, Backtracking https://leetcode.com/problems/additive-number Medium
Tree, Breadth-First Search, Design,
893 Binary Tree https://leetcode.com/problems/complete-binary-tree-inserter Medium
894 Array, Math https://leetcode.com/problems/three-equal-parts Hard
895 Enumeration https://leetcode.com/problems/sequential-digits Medium
896 Two Pointers, String, Prefix Sum https://leetcode.com/problems/jump-game-vii Medium
897 Array, Hash Table, String, Trie https://leetcode.com/problems/short-encoding-of-words Medium
898 String, Greedy https://leetcode.com/problems/break-a-palindrome Medium
Array, Hash Table, Two Pointers,
899 Binary Search, Sorting https://leetcode.com/problems/check-if-n-and-its-double-exist Easy
900 String, Stack https://leetcode.com/problems/maximum-nesting-depth-of-the-parentheses Easy
901 Array, Sorting, Heap (Priority Queue) https://leetcode.com/problems/single-threaded-cpu Medium
902 String, Sorting https://leetcode.com/problems/sorting-the-sentence Easy
903 Array, String, Sorting https://leetcode.com/problems/find-and-replace-in-string Medium
904 Array, Hash Table, Greedy, Prefix Sum https://leetcode.com/problems/maximum-number-of-non-overlapping-subarrays-with-sum-equals-target
Medium
905 Design, Segment Tree, Ordered Set https://leetcode.com/problems/my-calendar-iii Hard
906 Array, Binary Search, Sorting https://leetcode.com/problems/sum-of-mutated-array-closest-to-target Medium
907 String, Greedy https://leetcode.com/problems/partitioning-into-minimum-number-of-deci-binary-numbers
Medium
Dynamic Programming, Backtracking,
908 Bit Manipulation, Bitmask https://leetcode.com/problems/stickers-to-spell-word Hard
Math, Dynamic Programming,
909 Combinatorics https://leetcode.com/problems/number-of-music-playlists Hard
Array, Hash Table, String, Bit
910 Manipulation https://leetcode.com/problems/count-the-number-of-consistent-strings Easy
911 Tree, Depth-First Search, Binary Tree https://leetcode.com/problems/flip-binary-tree-to-match-preorder-traversal Medium
Tree, Depth-First Search, Breadth-First
Search, Union Find, Graph, Binary
912 Tree https://leetcode.com/problems/validate-binary-tree-nodes Medium
913 Math, Simulation https://leetcode.com/problems/distribute-candies-to-people Easy
914 Array https://leetcode.com/problems/number-of-times-binary-string-is-prefix-aligned Medium
Array, Math, Dynamic Programming,
915 Prefix Sum https://leetcode.com/problems/number-of-sub-arrays-with-odd-sum Medium
916 Math, Recursion https://leetcode.com/problems/power-of-three Easy
917 String, Sliding Window https://leetcode.com/problems/swap-for-longest-repeated-character-substring Medium
918 Math, Binary Search, Number Theory https://leetcode.com/problems/ugly-number-iii Medium
919 Array, Binary Search https://leetcode.com/problems/h-index-ii Medium
Hash Table, String, Bit Manipulation,
920 Rolling Hash, Hash Function https://leetcode.com/problems/check-if-a-string-contains-all-binary-codes-of-size-k
Medium
921 Array https://leetcode.com/problems/1-bit-and-2-bit-characters Easy
922 Array https://leetcode.com/problems/decompress-run-length-encoded-list Easy
 Depth-First Search, Breadth-First
923 Search, Graph, Topological Sort https://leetcode.com/problems/course-schedule-iv Medium
Array, Stack, Monotonic Stack, Prefix
924 Sum https://leetcode.com/problems/maximum-subarray-min-product Medium
Array, Dynamic Programming, Bit
925 Manipulation, Bitmask https://leetcode.com/problems/smallest-sufficient-team Hard
String, Dynamic Programming, Depth-
926 First Search, Breadth-First Search https://leetcode.com/problems/freedom-trail Hard
Tree, Depth-First Search, Breadth-First
927 Search, Binary Tree https://leetcode.com/problems/find-a-corresponding-node-of-a-binary-tree-in-a-clone-of-that-tree
Medium
928 Array, Dynamic Programming https://leetcode.com/problems/dice-roll-simulation Hard
Array, Two Pointers, Binary Search,
929 Prefix Sum https://leetcode.com/problems/ways-to-split-array-into-three-subarrays Medium
Math, Depth-First Search, Breadth-
930 First Search https://leetcode.com/problems/water-and-jug-problem Medium
931 String https://leetcode.com/problems/goat-latin Easy
932 Array, Math, Simulation https://leetcode.com/problems/cells-with-odd-values-in-a-matrix Easy
933 Array, String https://leetcode.com/problems/count-items-matching-a-rule Easy
934 Array, Simulation https://leetcode.com/problems/sum-of-even-numbers-after-queries Medium
935 Array, Math https://leetcode.com/problems/beautiful-arrangement-ii Medium
936 Hash Table, Linked List https://leetcode.com/problems/linked-list-components Medium
937 Array, Two Pointers, String https://leetcode.com/problems/expressive-words Medium
938 Array, Prefix Sum https://leetcode.com/problems/find-the-highest-altitude Easy
939 String, Stack https://leetcode.com/problems/make-the-string-great Easy
940 String https://leetcode.com/problems/validate-ip-address Medium
941 String, Dynamic Programming https://leetcode.com/problems/palindrome-partitioning-iii Hard
942 Array, String https://leetcode.com/problems/check-if-two-string-arrays-are-equivalent Easy
Array, Dynamic Programming, Depth-
943 First Search, Matrix, Simulation https://leetcode.com/problems/where-will-the-ball-fall Medium
944 Array, Stack, Queue, Simulation https://leetcode.com/problems/number-of-students-unable-to-eat-lunch Easy
945 Array, Heap (Priority Queue) https://leetcode.com/problems/construct-target-array-with-multiple-sums Hard
946 Math, Geometry https://leetcode.com/problems/valid-square Medium
947 Array, Dynamic Programming, Matrix https://leetcode.com/problems/minimum-falling-path-sum-ii Hard
Array, Math, Dynamic Programming,
948 Sorting https://leetcode.com/problems/allocate-mailboxes Hard
949 Array, Matrix, Simulation https://leetcode.com/problems/queens-that-can-attack-the-king Medium
Array, Hash Table, Binary Search,
950 Design https://leetcode.com/problems/online-election Medium
951 String, Sliding Window https://leetcode.com/problems/maximum-number-of-vowels-in-a-substring-of-given-length
Medium
952 Math, Simulation https://leetcode.com/problems/water-bottles Easy
953 Array, Hash Table https://leetcode.com/problems/check-array-formation-through-concatenation Easy
954 Array, Greedy, Sorting, Counting Sort https://leetcode.com/problems/array-partition-i Easy
955 Array, Two Pointers, Greedy, Sorting https://leetcode.com/problems/bag-of-tokens Medium
Array, Hash Table, Two Pointers,
956 Sorting https://leetcode.com/problems/max-number-of-k-sum-pairs Medium
957 Math, Binary Search https://leetcode.com/problems/nth-digit Medium
Math, Dynamic Programming,
958 Combinatorics https://leetcode.com/problems/poor-pigs Hard
959 Array https://leetcode.com/problems/concatenation-of-array Easy
960 Greedy https://leetcode.com/problems/find-the-minimum-number-of-fibonacci-numbers-whose-sum-is-k
Medium
961 Array, Hash Table, Sorting https://leetcode.com/problems/make-two-arrays-equal-by-reversing-sub-arrays Easy
Array, Math, Dynamic Programming,
Backtracking, Bit Manipulation,
962 Bitmask https://leetcode.com/problems/number-of-squareful-arrays Hard
Dynamic Programming, Graph,
963 Topological Sort, Shortest Path https://leetcode.com/problems/number-of-ways-to-arrive-at-destination Medium
Math, Dynamic Programming,
964 Recursion https://leetcode.com/problems/number-of-digit-one Hard
965 Array, Linked List, Design, Queue https://leetcode.com/problems/design-circular-deque Medium
966 Array, Math https://leetcode.com/problems/range-addition-ii Easy
Array, Math, Dynamic Programming,
967 Game Theory https://leetcode.com/problems/stone-game-vii Medium
968 Array, Hash Table, Sliding Window https://leetcode.com/problems/fruit-into-baskets Medium
969 Array, Dynamic Programming https://leetcode.com/problems/tallest-billboard Hard
970 Hash Table, String, Greedy, Counting https://leetcode.com/problems/construct-k-palindrome-strings Medium
971 String, Backtracking https://leetcode.com/problems/the-k-th-lexicographical-string-of-all-happy-strings-of-length-n
Medium
972 Hash Table, String https://leetcode.com/problems/alphabet-board-path Medium
Array, Dynamic Programming,
973 Breadth-First Search https://leetcode.com/problems/minimum-jumps-to-reach-home Medium
974 Hash Table, String, Sorting https://leetcode.com/problems/determine-if-two-strings-are-close Medium
975 Array, Hash Table, Counting https://leetcode.com/problems/sum-of-unique-elements Easy
976 Array https://leetcode.com/problems/element-appearing-more-than-25-in-sorted-array Easy
 977 Array, Sorting https://leetcode.com/problems/largest-number-at-least-twice-of-others Easy
978 Array, Hash Table, Math, Greedy https://leetcode.com/problems/rabbits-in-forest Medium
979 Dynamic Programming, Memoization https://leetcode.com/problems/minimum-number-of-days-to-eat-n-oranges Hard
980 String https://leetcode.com/problems/positions-of-large-groups Easy
981 Array, Math, Randomized https://leetcode.com/problems/shuffle-an-array Medium
982 Array, Dynamic Programming https://leetcode.com/problems/maximum-absolute-sum-of-any-subarray Medium
983 String, Counting https://leetcode.com/problems/minimum-number-of-frogs-croaking Medium
Array, Math, Binary Search, Greedy,
984 Sorting, Heap (Priority Queue) https://leetcode.com/problems/sell-diminishing-valued-colored-balls Medium
985 Array, Math, Prefix Sum https://leetcode.com/problems/sum-of-absolute-differences-in-a-sorted-array Medium
Math, Dynamic Programming, Breadth-
First Search, Graph, Memoization,
986 Game Theory https://leetcode.com/problems/cat-and-mouse Hard
Array, Math, Backtracking, Bit
987 Manipulation, Combinatorics https://leetcode.com/problems/sum-of-all-subset-xor-totals Easy
988 String, Greedy https://leetcode.com/problems/minimum-suffix-flips Medium
989 Array, Bit Manipulation https://leetcode.com/problems/decode-xored-array Easy
Array, Depth-First Search, Breadth-
990 First Search, Union Find, Matrix https://leetcode.com/problems/count-sub-islands Medium
991 Binary Search, Design, Ordered Set https://leetcode.com/problems/data-stream-as-disjoint-intervals Hard
Array, Breadth-First Search, Heap
992 (Priority Queue), Matrix https://leetcode.com/problems/minimum-moves-to-move-a-box-to-their-target-location
Hard
993 Array, Greedy, Sorting, Matrix https://leetcode.com/problems/largest-submatrix-with-rearrangements Medium
994 Array, Dynamic Programming, Sorting https://leetcode.com/problems/jump-game-v Hard
995 Array, Line Sweep https://leetcode.com/problems/perfect-rectangle Hard
String, Binary Search, Sliding Window,
996 Prefix Sum https://leetcode.com/problems/get-equal-substrings-within-budget Medium
String, Rolling Hash, String Matching,
997 Hash Function https://leetcode.com/problems/longest-happy-prefix Hard
Array, Binary Search, Dynamic
998 Programming, Greedy https://leetcode.com/problems/minimum-number-of-removals-to-make-mountain-array
Hard
Array, Binary Search, Dynamic
999 Programming https://leetcode.com/problems/make-array-strictly-increasing Hard
Hash Table, Math, Binary Search,
1000 Sorting, Randomized https://leetcode.com/problems/random-pick-with-blacklist Hard
 Crack The Coding Interview - Dinesh Varyani
https://www.youtube.com/user/hubberspot?sub_confirmation=1

# Topic Question Difficulty

Array, Depth-First Search, Breadth-

1001 First Search, Union Find, Matrix https://leetcode.com/problems/minimize-malware-spread Hard
Array, Greedy, Union Find, Graph,
1002 Topological Sort, Matrix https://leetcode.com/problems/rank-transform-of-a-matrix Hard
1003 String, Dynamic Programming, Stack https://leetcode.com/problems/minimum-deletions-to-make-string-balanced Medium
Depth-First Search, Breadth-First
1004 Search, Graph, Topological Sort https://leetcode.com/problems/sort-items-by-groups-respecting-dependencies Hard
1005 Array, Binary Search, Sorting https://leetcode.com/problems/special-array-with-x-elements-greater-than-or-equal-x
Easy
1006 Math https://leetcode.com/problems/the-kth-factor-of-n Medium
1007 Math, Dynamic Programming https://leetcode.com/problems/rotated-digits Medium
1008 String, Stack, Greedy https://leetcode.com/problems/minimum-insertions-to-balance-a-parentheses-string
Medium
1009 String https://leetcode.com/problems/longest-uncommon-subsequence-i Easy
1010 Array, Hash Table, Math https://leetcode.com/problems/number-of-boomerangs Medium
1011 Math, Sorting, Counting, Enumeration https://leetcode.com/problems/reordered-power-of-2 Medium
1012 Array, Hash Table, Counting https://leetcode.com/problems/find-lucky-integer-in-an-array Easy
1013 Graph https://leetcode.com/problems/maximal-network-rank Medium
1014 Math, Dynamic Programming https://leetcode.com/problems/egg-drop-with-2-eggs-and-n-floors Medium
Hash Table, String, Bit Manipulation,
1015 Prefix Sum https://leetcode.com/problems/number-of-wonderful-substrings Medium
1016 String, Stack, Recursion https://leetcode.com/problems/parsing-a-boolean-expression Hard
Tree, Breadth-First Search, Binary
1017 Tree https://leetcode.com/problems/even-odd-tree Medium
1018 Array, Stack, Monotonic Stack https://leetcode.com/problems/number-of-visible-people-in-a-queue Hard
1019 Array, String https://leetcode.com/problems/remove-comments Medium
Array, String, Dynamic Programming,
Backtracking, Bit Manipulation,
1020 Bitmask https://leetcode.com/problems/maximum-score-words-formed-by-letters Hard
Math, Dynamic Programming, Game
1021 Theory https://leetcode.com/problems/stone-game-iv Hard
Array, Dynamic Programming, Bit
1022 Manipulation, Bitmask https://leetcode.com/problems/number-of-ways-to-wear-different-hats-to-each-other
Hard
1023 Array, Hash Table https://leetcode.com/problems/restore-the-array-from-adjacent-pairs Medium
1024 Hash Table, String https://leetcode.com/problems/check-if-the-sentence-is-pangram Easy
1025 Array, Math, Geometry https://leetcode.com/problems/erect-the-fence Hard
Array, Depth-First Search, Graph,
1026 Topological Sort https://leetcode.com/problems/loud-and-rich Medium
1027 Array, Dynamic Programming https://leetcode.com/problems/max-dot-product-of-two-subsequences Hard
1028 Math, String, Sorting https://leetcode.com/problems/orderly-queue Hard
1029 Array, String, Trie https://leetcode.com/problems/remove-sub-folders-from-the-filesystem Medium
Dynamic Programming, Bit
1030 Manipulation, Graph, Bitmask https://leetcode.com/problems/parallel-courses-ii Hard
1031 String https://leetcode.com/problems/goal-parser-interpretation Easy
1032 String, Greedy https://leetcode.com/problems/minimum-number-of-flips-to-make-the-binary-string-alternating
Medium
1033 String, Greedy https://leetcode.com/problems/smallest-string-with-a-given-numeric-value Medium
Hash Table, String, Dynamic
1034 Programming https://leetcode.com/problems/count-substrings-that-differ-by-one-character Medium
1035 Hash Table, String, Sliding Window https://leetcode.com/problems/maximum-number-of-occurrences-of-a-substring Medium
Array, Dynamic Programming, Bit
1036 Manipulation, Matrix, Bitmask https://leetcode.com/problems/maximum-students-taking-exam Hard
1037 String, Enumeration https://leetcode.com/problems/largest-time-for-given-digits Medium
1038 Design, Simulation, Counting https://leetcode.com/problems/design-parking-system Easy
1039 Array, Dynamic Programming https://leetcode.com/problems/maximum-score-from-performing-multiplication-operations
Medium
Array, Math, Stack, Heap (Priority
1040 Queue), Monotonic Stack https://leetcode.com/problems/car-fleet-ii Hard
1041 Union Find, Graph https://leetcode.com/problems/remove-max-number-of-edges-to-keep-graph-fully-traversable
Hard
1042 Trie https://leetcode.com/problems/k-th-smallest-in-lexicographical-order Hard
Depth-First Search, Breadth-First
1043 Search, Graph https://leetcode.com/problems/find-if-path-exists-in-graph Easy
Tree, Depth-First Search, Breadth-First
1044 Search, Design, Binary Tree https://leetcode.com/problems/find-elements-in-a-contaminated-binary-tree Medium
Array, Math, Greedy, Sorting, Game
1045 Theory https://leetcode.com/problems/maximum-number-of-coins-you-can-get Medium
1046 String, Stack, Greedy, Queue https://leetcode.com/problems/stamping-the-sequence Hard
1047 Hash Table, Math, String https://leetcode.com/problems/reconstruct-original-digits-from-english Medium
1048 Array https://leetcode.com/problems/number-of-students-doing-homework-at-a-given-time
Easy
Array, Greedy, Heap (Priority Queue),
1049 Ordered Set https://leetcode.com/problems/minimize-deviation-in-array Hard
 Array, Two Pointers, Dynamic
1050 Programming, Greedy https://leetcode.com/problems/get-the-maximum-score Hard
1051 Array, Dynamic Programming https://leetcode.com/problems/maximum-alternating-subsequence-sum Medium
1052 String, Recursion https://leetcode.com/problems/special-binary-string Hard
1053 String, Stack https://leetcode.com/problems/check-if-word-is-valid-after-substitutions Medium
1054 Array, Sorting https://leetcode.com/problems/can-make-arithmetic-progression-from-sequence Easy
1055 Array, Greedy https://leetcode.com/problems/super-washing-machines Hard
1056 Math, Simulation https://leetcode.com/problems/count-of-matches-in-tournament Easy
1057 Math https://leetcode.com/problems/perfect-number Easy
1058 Binary Search, Interactive https://leetcode.com/problems/guess-number-higher-or-lower Easy
1059 Array, Depth-First Search, Union Find https://leetcode.com/problems/minimize-hamming-distance-after-swap-operations
Medium
Hash Table, String, Bit Manipulation,
1060 Prefix Sum https://leetcode.com/problems/can-make-palindrome-from-substring Medium
Array, Depth-First Search, Breadth-
1061 First Search, Union Find, Matrix https://leetcode.com/problems/check-if-there-is-a-valid-path-in-a-grid Medium
Array, Depth-First Search, Breadth-
1062 First Search, Union Find, Matrix https://leetcode.com/problems/detect-cycles-in-2d-grid Medium
Dynamic Programming, Graph,
Topological Sort, Heap (Priority
1063 Queue), Shortest Path https://leetcode.com/problems/number-of-restricted-paths-from-first-to-last-nodeMedium
Two Pointers, String, Trie, String
1064 Matching https://leetcode.com/problems/camelcase-matching Medium
1065 Array, Dynamic Programming, Greedy https://leetcode.com/problems/minimum-sideway-jumps Medium
Array, Two Pointers, Binary Search,
1066 Sorting https://leetcode.com/problems/friends-of-appropriate-ages Medium
Array, Dynamic Programming, Greedy,
1067 Heap (Priority Queue) https://leetcode.com/problems/pizza-with-3n-slices Hard
1068 Dynamic Programming https://leetcode.com/problems/number-of-ways-to-stay-in-the-same-place-after-some-steps
Hard
Array, Binary Search, Divide and
1069 Conquer, Matrix https://leetcode.com/problems/find-a-peak-element-ii Medium
1070 Two Pointers, String, Stack, Greedy https://leetcode.com/problems/minimum-number-of-swaps-to-make-the-string-balanced
Medium
Array, Two Pointers, Binary Search,
1071 Sorting https://leetcode.com/problems/range-sum-of-sorted-subarray-sums Medium
1072 Hash Table, String, Backtracking https://leetcode.com/problems/split-a-string-into-the-max-number-of-unique-substrings
Medium
Graph, Heap (Priority Queue), Shortest
1073 Path https://leetcode.com/problems/reachable-nodes-in-subdivided-graph Hard
1074 Array https://leetcode.com/problems/distance-between-bus-stops Easy
1075 Array, Dynamic Programming https://leetcode.com/problems/paint-house-iii Hard
1076 Array, Heap (Priority Queue) https://leetcode.com/problems/process-tasks-using-servers Medium
1077 Array, String, Binary Search https://leetcode.com/problems/maximum-number-of-removable-characters Medium
1078 Array, Hash Table, Matrix https://leetcode.com/problems/flip-columns-for-maximum-number-of-equal-rowsMedium
1079 Array, Design, Counting, Iterator https://leetcode.com/problems/rle-iterator Medium
1080 Array https://leetcode.com/problems/binary-prefix-divisible-by-5 Easy
1081 Array, String https://leetcode.com/problems/slowest-key Easy
Array, Two Pointers, Binary Search,
1082 Stack, Monotonic Stack https://leetcode.com/problems/maximum-score-of-a-good-subarray Hard
1083 Array, Two Pointers, Greedy, Sorting https://leetcode.com/problems/minimize-maximum-pair-sum-in-array Medium
1084 Math, String, Simulation https://leetcode.com/problems/complex-number-multiplication Medium
1085 Array, Dynamic Programming, Matrix https://leetcode.com/problems/maximum-non-negative-product-in-a-matrix Medium
Array, Stack, Greedy, Sorting,
1086 Monotonic Stack https://leetcode.com/problems/the-number-of-weak-characters-in-the-game Medium
1087 Hash Table, String, Counting https://leetcode.com/problems/increasing-decreasing-string Easy
1088 Hash Table, String, Bit Manipulation https://leetcode.com/problems/find-longest-awesome-substring Hard
Array, Hash Table, String, Binary
1089 Search, Sorting https://leetcode.com/problems/compare-strings-by-frequency-of-the-smallest-character
Medium
Array, Bit Manipulation, Breadth-First
1090 Search, Matrix https://leetcode.com/problems/minimum-number-of-flips-to-convert-binary-matrix-to-zero-matrix
Hard
1091 Array, Sorting https://leetcode.com/problems/arithmetic-subarrays Medium
1092 Array, Dynamic Programming https://leetcode.com/problems/form-largest-integer-with-digits-that-add-up-to-target
Hard
1093 Math, String https://leetcode.com/problems/number-of-substrings-with-only-1s Medium
1094 String https://leetcode.com/problems/length-of-last-word Easy
1095 String, String Matching https://leetcode.com/problems/string-matching-in-an-array Easy
1096 Array, Sliding Window https://leetcode.com/problems/number-of-sub-arrays-of-size-k-and-average-greater-than-or-equal-to-threshold
Medium
Math, Dynamic Programming,
1097 Combinatorics https://leetcode.com/problems/count-all-valid-pickup-and-delivery-options Hard
1098 Array, Two Pointers, Matrix https://leetcode.com/problems/rotating-the-box Medium
1099 String, Greedy, Sorting https://leetcode.com/problems/check-if-a-string-can-break-another-string Medium
1100 Array, Dynamic Programming, Matrix https://leetcode.com/problems/largest-1-bordered-square Medium
1101 String https://leetcode.com/problems/maximum-score-after-splitting-a-string Easy
1102 Array, Hash Table https://leetcode.com/problems/count-good-meals Medium
1103 Math, String https://leetcode.com/problems/find-the-closest-palindrome Hard
1104 Math https://leetcode.com/problems/check-if-number-is-a-sum-of-powers-of-three Medium
1105 Two Pointers, String, Greedy https://leetcode.com/problems/split-two-strings-to-make-palindrome Medium
Bit Manipulation, Depth-First Search,
1106 Breadth-First Search https://leetcode.com/problems/pyramid-transition-matrix Medium
1107 String, String Matching https://leetcode.com/problems/check-if-a-word-occurs-as-a-prefix-of-any-word-in-a-sentence
Easy
1108 Array, Greedy https://leetcode.com/problems/minimum-operations-to-make-the-array-increasing Easy
1109 Array, Matrix, Simulation https://leetcode.com/problems/spiral-matrix-iii Medium
1110 Array, Hash Table, Counting https://leetcode.com/problems/number-of-equivalent-domino-pairs Easy
1111 Array, Math, Geometry, Sorting, Matrix https://leetcode.com/problems/matrix-cells-in-distance-order Easy
1112 Hash Table, String https://leetcode.com/problems/path-crossing Easy
1113 Array, Greedy, Sorting, Prefix Sum https://leetcode.com/problems/maximum-sum-obtained-of-any-permutation Medium
1114 Array, Breadth-First Search, Matrix https://leetcode.com/problems/map-of-highest-peak Medium
1115 String, Greedy, Heap (Priority Queue) https://leetcode.com/problems/strong-password-checker Hard
1116 Array, Matrix, Simulation https://leetcode.com/problems/shift-2d-grid Easy
Array, Binary Search, Divide and
Conquer, Binary Indexed Tree,
Segment Tree, Merge Sort, Ordered
1117 Set https://leetcode.com/problems/create-sorted-array-through-instructions Hard
1118 String, Greedy https://leetcode.com/problems/string-without-aaa-or-bbb Medium
1119 String, Sorting https://leetcode.com/problems/rearrange-words-in-a-sentence Medium
1120 String, Counting https://leetcode.com/problems/determine-if-string-halves-are-alike Easy
1121 Array, Greedy, Heap (Priority Queue) https://leetcode.com/problems/maximum-number-of-eaten-apples Medium
1122 Array, Math, Sorting https://leetcode.com/problems/sum-of-subsequence-widths Hard
1123 Dynamic Programming https://leetcode.com/problems/valid-permutations-for-di-sequence Hard
1124 Array, Greedy, Heap (Priority Queue) https://leetcode.com/problems/maximum-average-pass-ratio Medium
Array, Dynamic Programming,
Backtracking, Bit Manipulation,
1125 Bitmask https://leetcode.com/problems/find-minimum-time-to-finish-all-jobs Hard
1126 String, Greedy https://leetcode.com/problems/maximum-number-of-non-overlapping-substringsHard
1127 Array, Enumeration https://leetcode.com/problems/detect-pattern-of-length-m-repeated-k-or-more-times
Easy
1128 Array, String, Greedy https://leetcode.com/problems/delete-columns-to-make-sorted-ii Medium
1129 Array, Bit Manipulation https://leetcode.com/problems/decode-xored-permutation Medium
1130 Array, Greedy, Sorting https://leetcode.com/problems/set-intersection-size-at-least-two Hard
Array, Divide and Conquer, Tree,
1131 Matrix https://leetcode.com/problems/construct-quad-tree Medium
1132 Array, Simulation https://leetcode.com/problems/find-the-winner-of-an-array-game Medium
1133 Array, Hash Table, Greedy, Counting https://leetcode.com/problems/equal-sum-arrays-with-minimum-number-of-operations
Medium
1134 Binary Search, Greedy https://leetcode.com/problems/maximum-value-at-a-given-index-in-a-bounded-array
Medium
1135 Array, Breadth-First Search, Matrix https://leetcode.com/problems/snakes-and-ladders Medium
Array, Binary Search, Design, Binary
1136 Indexed Tree, Segment Tree https://leetcode.com/problems/online-majority-element-in-subarray Hard
1137 String, Bit Manipulation https://leetcode.com/problems/number-of-steps-to-reduce-a-number-in-binary-representation-to-one
Medium
1138 Math https://leetcode.com/problems/base-7 Easy
1139 Array, Segment Tree, Ordered Set https://leetcode.com/problems/falling-squares Hard
1140 Two Pointers, String https://leetcode.com/problems/last-substring-in-lexicographical-order Hard
1141 Array, Math https://leetcode.com/problems/maximum-of-absolute-value-expression Medium
1142 Array, Union Find, Graph, Sorting https://leetcode.com/problems/checking-existence-of-edge-length-limited-paths Hard
1143 Math, Bit Manipulation https://leetcode.com/problems/prime-number-of-set-bits-in-binary-representationEasy
Array, Hash Table, Depth-First Search,
1144 Breadth-First Search https://leetcode.com/problems/escape-a-large-maze Hard
1145 Dynamic Programming, Backtracking https://leetcode.com/problems/tiling-a-rectangle-with-the-fewest-squares Hard
1146 Array, Counting https://leetcode.com/problems/maximum-population-year Easy
1147 Math, Divide and Conquer https://leetcode.com/problems/super-pow Medium
1148 Array, Binary Search, Simulation https://leetcode.com/problems/find-latest-group-of-size-m Medium
Hash Table, String, Bit Manipulation,
1149 Sliding Window https://leetcode.com/problems/longest-nice-substring Easy
1150 String https://leetcode.com/problems/remove-all-occurrences-of-a-substring Medium
Array, Dynamic Programming,
Backtracking, Bit Manipulation,
1151 Bitmask https://leetcode.com/problems/minimum-number-of-work-sessions-to-finish-the-tasks
Medium
1152 Array, Stack, Simulation https://leetcode.com/problems/build-an-array-with-stack-operations Easy
1153 Array, Greedy https://leetcode.com/problems/maximum-number-of-consecutive-values-you-can-make
Medium
Array, Math, Greedy, Sorting, Heap
1154 (Priority Queue), Game Theory https://leetcode.com/problems/stone-game-vi Medium
Array, Two Pointers, Binary Search,
1155 Greedy https://leetcode.com/problems/maximum-distance-between-a-pair-of-values Medium
1156 Array, Matrix, Simulation https://leetcode.com/problems/available-captures-for-rook Easy
1157 String, Dynamic Programming https://leetcode.com/problems/string-compression-ii Hard
Math, Dynamic Programming,
1158 Combinatorics https://leetcode.com/problems/number-of-ways-to-rearrange-sticks-with-k-sticks-visible
Hard
1159 Array, Matrix https://leetcode.com/problems/determine-whether-matrix-can-be-obtained-by-rotation
Easy
1160 Array, Dynamic Programming, Sorting https://leetcode.com/problems/maximum-height-by-stacking-cuboids Hard
1161 Array, Hash Table, String https://leetcode.com/problems/groups-of-special-equivalent-strings Medium
Array, Dynamic Programming,
1162 Memoization, Matrix https://leetcode.com/problems/number-of-ways-of-cutting-a-pizza Hard
1163 String, Dynamic Programming https://leetcode.com/problems/palindrome-partitioning-iv Hard
1164 Array, Sorting https://leetcode.com/problems/average-salary-excluding-the-minimum-and-maximum-salary
Easy
1165 Math, Greedy, Heap (Priority Queue) https://leetcode.com/problems/maximum-score-from-removing-stones Medium
Array, Binary Search, Sorting, Ordered
1166 Set https://leetcode.com/problems/minimum-absolute-sum-difference Medium
1167 Array, Math, Geometry https://leetcode.com/problems/queries-on-number-of-points-inside-a-circle Medium
1168 String, Greedy, Queue https://leetcode.com/problems/dota2-senate Medium
1169 Array, String, Dynamic Programming https://leetcode.com/problems/delete-columns-to-make-sorted-iii Hard
Union Find, Graph, Sorting, Minimum
Spanning Tree, Strongly Connected
1170 Component https://leetcode.com/problems/find-critical-and-pseudo-critical-edges-in-minimum-spanning-tree
Hard
Array, Binary Search, Dynamic
1171 Programming, Sorting https://leetcode.com/problems/maximum-earnings-from-taxi Medium
1172 String https://leetcode.com/problems/number-of-segments-in-a-string Easy
1173 String https://leetcode.com/problems/valid-number Hard
Hash Table, String, Sliding Window,
1174 Counting https://leetcode.com/problems/substrings-of-size-three-with-distinct-characters Easy
1175 Array, Dynamic Programming https://leetcode.com/problems/profitable-schemes Hard
1176 Array, String, Stack https://leetcode.com/problems/crawler-log-folder Easy
1177 Math, Bit Manipulation https://leetcode.com/problems/binary-gap Easy
Two Pointers, String, Dynamic
Programming, Greedy, Rolling Hash,
1178 Hash Function https://leetcode.com/problems/longest-chunked-palindrome-decomposition Hard
1179 Array https://leetcode.com/problems/check-if-array-is-sorted-and-rotated Easy
Array, Hash Table, Greedy, Bit
1180 Manipulation https://leetcode.com/problems/cinema-seat-allocation Medium
1181 String, Recursion https://leetcode.com/problems/find-kth-bit-in-nth-binary-string Medium
1182 Array, Hash Table, Prefix Sum https://leetcode.com/problems/minimum-moves-to-make-array-complementary Medium
Array, Binary Search, Dynamic
1183 Programming https://leetcode.com/problems/maximum-number-of-events-that-can-be-attended-ii
Hard
1184 Two Pointers, String https://leetcode.com/problems/merge-strings-alternately Easy
1185 Math, String https://leetcode.com/problems/number-of-ways-to-split-a-string Medium
1186 Array, Math https://leetcode.com/problems/smallest-range-i Easy
1187 Math https://leetcode.com/problems/calculate-money-in-leetcode-bank Easy
1188 Array, Math, Geometry, Matrix https://leetcode.com/problems/surface-area-of-3d-shapes Easy
1189 Dynamic Programming https://leetcode.com/problems/build-array-where-you-can-find-the-maximum-exactly-k-comparisons
Hard
Array, Depth-First Search, Breadth-
1190 First Search, Union Find, Matrix https://leetcode.com/problems/minimize-malware-spread-ii Hard
1191 Array, String, Simulation https://leetcode.com/problems/print-words-vertically Medium
1192 Bit Manipulation https://leetcode.com/problems/minimum-flips-to-make-a-or-b-equal-to-c Medium
1193 Array, Matrix https://leetcode.com/problems/special-positions-in-a-binary-matrix Easy
Array, Two Pointers, Dynamic
Programming, Bit Manipulation,
1194 Bitmask https://leetcode.com/problems/closest-subsequence-sum Hard
1195 Hash Table, String, Stack, Recursion https://leetcode.com/problems/parse-lisp-expression Hard
Hash Table, Dynamic Programming,
Graph, Topological Sort, Memoization,
1196 Counting https://leetcode.com/problems/largest-color-value-in-a-directed-graph Hard
1197 Array, Dynamic Programming, Matrix https://leetcode.com/problems/minimize-the-difference-between-target-and-chosen-elements
Medium
1198 Array, String https://leetcode.com/problems/truncate-sentence Easy
1199 Array, Binary Search https://leetcode.com/problems/minimum-speed-to-arrive-on-time Medium
1200 Hash Table, String, Prefix Sum https://leetcode.com/problems/unique-length-3-palindromic-subsequences Medium
1201 Array, Binary Search https://leetcode.com/problems/minimum-operations-to-make-the-array-k-increasing
Hard
Math, Binary Search, Reservoir
Sampling, Prefix Sum, Ordered Set,
1202 Randomized https://leetcode.com/problems/random-point-in-non-overlapping-rectangles Medium
1203 Math, Dynamic Programming https://leetcode.com/problems/numbers-with-repeated-digits Hard
1204 Array, Greedy https://leetcode.com/problems/minimum-numbers-of-function-calls-to-make-target-array
Medium
1205 Array, Greedy, Matrix https://leetcode.com/problems/minimum-swaps-to-arrange-a-binary-grid Medium
Array, Binary Search, Depth-First
Search, Breadth-First Search, Union
1206 Find, Matrix https://leetcode.com/problems/last-day-where-you-can-still-cross Hard
1207 Dynamic Programming, Graph https://leetcode.com/problems/minimum-cost-to-reach-destination-in-time Hard
1208 Array, String, Backtracking https://leetcode.com/problems/find-unique-binary-string Medium
1209 Math https://leetcode.com/problems/construct-the-rectangle Easy
Array, Greedy, Sliding Window, Prefix
1210 Sum https://leetcode.com/problems/minimum-adjacent-swaps-for-k-consecutive-onesHard
1211 Array, Enumeration https://leetcode.com/problems/count-good-triplets Easy
1212 Array, String https://leetcode.com/problems/valid-tic-tac-toe-state Medium
1213 Array, Math, Geometry, Matrix https://leetcode.com/problems/projection-area-of-3d-shapes Easy
1214 Array, Hash Table https://leetcode.com/problems/grid-illumination Hard
Array, Hash Table, Binary Search,
1215 Greedy https://leetcode.com/problems/minimum-operations-to-make-a-subsequence Hard
1216 Array, Two Pointers, Sorting https://leetcode.com/problems/the-k-strongest-values-in-an-array Medium
1217 Graph https://leetcode.com/problems/find-center-of-star-graph Easy
Array, Linked List, Design, Queue,
1218 Data Stream https://leetcode.com/problems/design-front-middle-back-queue Medium
Array, Dynamic Programming,
Backtracking, Bit Manipulation,
1219 Bitmask https://leetcode.com/problems/maximum-compatibility-score-sum Medium
1220 Array, Matrix, Prefix Sum https://leetcode.com/problems/grid-game Medium
1221 Tree, Depth-First Search, Binary Tree https://leetcode.com/problems/insufficient-nodes-in-root-to-leaf-paths Medium
1222 Array, Math https://leetcode.com/problems/sign-of-the-product-of-an-array Easy
Array, Math, Divide and Conquer,
Dynamic Programming, Tree, Union
Find, Binary Search Tree,
Memoization, Combinatorics, Binary
1223 Tree https://leetcode.com/problems/number-of-ways-to-reorder-array-to-get-same-bstHard
1224 Array https://leetcode.com/problems/defuse-the-bomb Easy
1225 Array, Hash Table https://leetcode.com/problems/tuple-with-same-product Medium
1226 String https://leetcode.com/problems/minimum-changes-to-make-alternating-binary-stringEasy
1227 String https://leetcode.com/problems/reformat-the-string Easy
1228 Array, Matrix https://leetcode.com/problems/image-smoother Easy
1229 Math, Geometry https://leetcode.com/problems/mirror-reflection Medium
1230 Array, Dynamic Programming, Greedy https://leetcode.com/problems/largest-multiple-of-three Hard
1231 String https://leetcode.com/problems/replace-all-s-to-avoid-consecutive-repeating-characters
Easy
1232 Array, Hash Table, Greedy, Sorting https://leetcode.com/problems/find-original-array-from-doubled-array Medium
1233 Array, String https://leetcode.com/problems/number-of-lines-to-write-string Easy
1234 Linked List, Design https://leetcode.com/problems/design-skiplist Hard
Tree, Depth-First Search, Breadth-First
1235 Search, Graph https://leetcode.com/problems/frog-position-after-t-seconds Hard
1236 Array, Bit Manipulation, Trie https://leetcode.com/problems/maximum-xor-with-an-element-from-array Hard
1237 Array https://leetcode.com/problems/check-if-all-1s-are-at-least-length-k-places-away Easy
Array, Hash Table, Two Pointers,
1238 String, Sorting https://leetcode.com/problems/longest-uncommon-subsequence-ii Medium
1239 Array, Hash Table, Math, Counting https://leetcode.com/problems/count-nice-pairs-in-an-array Medium
1240 String, Stack, Depth-First Search https://leetcode.com/problems/mini-parser Medium
1241 Math, String, Simulation https://leetcode.com/problems/solve-the-equation Medium
String, Tree, Depth-First Search,
1242 Binary Tree https://leetcode.com/problems/step-by-step-directions-from-a-binary-tree-node-to-another
Medium
1243 Array, Bit Manipulation https://leetcode.com/problems/utf-8-validation Medium
Tree, Depth-First Search, Breadth-First
1244 Search https://leetcode.com/problems/number-of-nodes-in-the-sub-tree-with-the-same-label
Medium
1245 Array, Backtracking https://leetcode.com/problems/construct-the-lexicographically-largest-valid-sequence
Medium
1246 Array https://leetcode.com/problems/remove-one-element-to-make-the-array-strictly-increasing
Easy
Math, Geometry, Rejection Sampling,
1247 Randomized https://leetcode.com/problems/generate-random-point-in-a-circle Medium
String, Backtracking, Stack, Breadth-
1248 First Search https://leetcode.com/problems/brace-expansion-ii Hard
1249 Two Pointers, String, Greedy https://leetcode.com/problems/minimum-adjacent-swaps-to-reach-the-kth-smallest-number
Medium
1250 String, Stack, Greedy https://leetcode.com/problems/maximum-score-from-removing-substrings Medium
Array, Dynamic Programming, Bit
1251 Manipulation, Bitmask https://leetcode.com/problems/minimum-xor-sum-of-two-arrays Hard
Array, Dynamic Programming,
1252 Backtracking https://leetcode.com/problems/closest-dessert-cost Medium
1253 String, Sliding Window https://leetcode.com/problems/longest-substring-of-all-vowels-in-order Medium
1254 Array, Hash Table https://leetcode.com/problems/maximum-equal-frequency Hard
1255 Math, String https://leetcode.com/problems/count-number-of-homogenous-substrings Medium
1256 Math, String https://leetcode.com/problems/determine-color-of-a-chessboard-square Easy
Array, Depth-First Search, Breadth-
1257 First Search, Matrix https://leetcode.com/problems/coloring-a-border Medium
Array, Heap (Priority Queue), Ordered
1258 Set https://leetcode.com/problems/the-number-of-the-smallest-unoccupied-chair Medium
1259 Array, Hash Table, String https://leetcode.com/problems/vowel-spellchecker Medium
1260 Hash Table, String https://leetcode.com/problems/largest-substring-between-two-equal-characters Easy
1261 Array, Dynamic Programming https://leetcode.com/problems/minimum-total-space-wasted-with-k-resizing-operations
Medium
1262 Linked List, Two Pointers https://leetcode.com/problems/delete-the-middle-node-of-a-linked-list Medium
Math, Dynamic Programming,
1263 Brainteaser, Probability and Statistics https://leetcode.com/problems/airplane-seat-assignment-probability Medium
Array, Depth-First Search, Breadth-
First Search, Matrix, Strongly
1264 Connected Component https://leetcode.com/problems/minimum-number-of-days-to-disconnect-island Hard
1265 Array, Hash Table, Prefix Sum https://leetcode.com/problems/intervals-between-identical-elements Medium
1266 Array, Hash Table https://leetcode.com/problems/minimum-absolute-difference-queries Medium
1267 String, String Matching https://leetcode.com/problems/maximum-repeating-substring Easy
1268 Tree, Binary Tree https://leetcode.com/problems/maximum-binary-tree-ii Medium
1269 Array https://leetcode.com/problems/maximum-ascending-subarray-sum Easy
String, Dynamic Programming,
1270 Breadth-First Search, Memoization https://leetcode.com/problems/zuma-game Hard
String, Dynamic Programming,
Backtracking, Bit Manipulation,
1271 Bitmask https://leetcode.com/problems/maximum-product-of-the-length-of-two-palindromic-subsequences
Medium
1272 Array, Prefix Sum https://leetcode.com/problems/smallest-rotation-with-highest-score Hard
1273 Array, String https://leetcode.com/problems/delete-columns-to-make-sorted Easy
1274 String, Dynamic Programming https://leetcode.com/problems/restore-the-array Hard
Array, Math, Dynamic Programming,
Backtracking, Bit Manipulation,
1275 Number Theory, Bitmask https://leetcode.com/problems/maximize-score-after-n-operations Hard
1276 Array, Design, Matrix https://leetcode.com/problems/subrectangle-queries Medium
1277 Array, Greedy, Sorting https://leetcode.com/problems/minimum-initial-energy-to-finish-tasks Hard
1278 Array https://leetcode.com/problems/count-number-of-pairs-with-absolute-difference-kEasy
1279 Hash Table, Math, Counting https://leetcode.com/problems/maximum-number-of-balls-in-a-box Easy
Array, Binary Search, Binary Indexed
1280 Tree https://leetcode.com/problems/find-the-longest-valid-obstacle-course-at-each-position
Hard
Math, Two Pointers, Binary Search,
1281 Interactive https://leetcode.com/problems/find-positive-integer-solution-for-a-given-equationMedium
Array, Math, Geometry, Sliding
1282 Window, Sorting https://leetcode.com/problems/maximum-number-of-visible-points Hard
Array, Math, Dynamic Programming,
1283 Game Theory https://leetcode.com/problems/stone-game-v Hard
1284 String, Greedy, Sorting https://leetcode.com/problems/check-if-string-is-transformable-with-substring-sort-operations
Hard
1285 Math, Bit Manipulation, Simulation https://leetcode.com/problems/concatenation-of-consecutive-binary-numbers Medium
1286 Math https://leetcode.com/problems/convert-to-base-2 Medium
Array, Dynamic Programming,
1287 Memoization https://leetcode.com/problems/count-all-possible-routes Hard
1288 Array https://leetcode.com/problems/three-consecutive-odds Easy
1289 Array, Hash Table https://leetcode.com/problems/finding-the-users-active-minutes Medium
Array, Binary Search, Line Sweep,
1290 Sorting, Heap (Priority Queue) https://leetcode.com/problems/minimum-interval-to-include-each-query Hard
1291 String https://leetcode.com/problems/replace-all-digits-with-characters Easy
1292 Array, Dynamic Programming https://leetcode.com/problems/count-number-of-special-subsequences Hard
1293 Array, Math, Greedy https://leetcode.com/problems/reverse-subarray-to-maximize-array-value Hard
1294 Array, Greedy, Sorting https://leetcode.com/problems/minimum-subsequence-in-non-increasing-order Easy
1295 String, Dynamic Programming https://leetcode.com/problems/maximize-palindrome-length-from-subsequences Hard
1296 Array, Sorting, Counting Sort https://leetcode.com/problems/height-checker Easy
Depth-First Search, Breadth-First
1297 Search, Union Find, Graph, Sorting https://leetcode.com/problems/find-all-people-with-secret Hard
1298 Array, Bit Manipulation, Prefix Sum https://leetcode.com/problems/maximum-xor-for-each-query Medium
1299 Array, Greedy https://leetcode.com/problems/maximum-number-of-weeks-for-which-you-can-work
Medium
Array, Math, Dynamic Programming,
1300 Combinatorics https://leetcode.com/problems/kth-smallest-instructions Hard
1301 Array, Math, Geometry https://leetcode.com/problems/largest-triangle-area Easy
1302 Array, Sorting https://leetcode.com/problems/maximum-product-difference-between-two-pairs Easy
1303 Array, Breadth-First Search, Matrix https://leetcode.com/problems/nearest-exit-from-entrance-in-maze Medium
Hash Table, Stack, Design, Heap
1304 (Priority Queue) https://leetcode.com/problems/dinner-plate-stacks Hard
1305 Hash Table, String, Counting https://leetcode.com/problems/check-if-one-string-swap-can-make-strings-equal Easy
1306 Array, Brainteaser, Simulation https://leetcode.com/problems/last-moment-before-all-ants-fall-out-of-a-plank Medium
1307 String https://leetcode.com/problems/occurrences-after-bigram Easy
1308 String, Dynamic Programming https://leetcode.com/problems/number-of-unique-good-subsequences Hard
1309 Array, Binary Indexed Tree, Simulation https://leetcode.com/problems/queries-on-a-permutation-with-key Medium
1310 Math https://leetcode.com/problems/prime-palindrome Medium
1311 Array, Hash Table, String https://leetcode.com/problems/making-file-names-unique Medium
1312 Two Pointers, String, Greedy https://leetcode.com/problems/largest-merge-of-two-strings Medium
String, Binary Search, Sliding Window,
1313 Prefix Sum https://leetcode.com/problems/maximize-the-confusion-of-an-exam Medium
1314 Array, Sorting, Heap (Priority Queue) https://leetcode.com/problems/relative-ranks Easy
1315 String https://leetcode.com/problems/thousand-separator Easy
1316 Math, Enumeration https://leetcode.com/problems/super-palindromes Hard
1317 Array, Greedy, Matrix https://leetcode.com/problems/reconstruct-a-2-row-binary-matrix Medium
Array, Dynamic Programming, Bit
1318 Manipulation, Matrix, Bitmask https://leetcode.com/problems/minimum-cost-to-connect-two-groups-of-points Hard
Array, Dynamic Programming,
1319 Simulation https://leetcode.com/problems/get-maximum-in-generated-array Easy
1320 Math, String, Greedy https://leetcode.com/problems/largest-odd-number-in-string Easy
1321 Array, Simulation https://leetcode.com/problems/average-waiting-time Medium
1322 Array, Binary Search https://leetcode.com/problems/minimum-number-of-operations-to-make-array-continuous
Hard
Array, Two Pointers, Binary Search,
Dynamic Programming, Bit
1323 Manipulation, Ordered Set, Bitmask https://leetcode.com/problems/partition-array-into-two-arrays-to-minimize-sum-difference
Hard
1324 Array, Stack, Monotonic Stack https://leetcode.com/problems/sum-of-subarray-ranges Medium
Array, Binary Search, Dynamic
Programming, Sorting, Heap (Priority
1325 Queue) https://leetcode.com/problems/two-best-non-overlapping-events Medium
1326 Array, Binary Search, Sorting https://leetcode.com/problems/closest-room Hard
1327 Array, Breadth-First Search https://leetcode.com/problems/minimum-operations-to-convert-number Medium
1328 Array, Math, Union Find https://leetcode.com/problems/graph-connectivity-with-threshold Hard
1329 Array, Dynamic Programming https://leetcode.com/problems/first-day-where-you-have-been-in-all-the-rooms Medium
1330 Array https://leetcode.com/problems/number-of-rectangles-that-can-form-the-largest-square
Easy
Math, Binary Search, Prefix Sum,
1331 Randomized https://leetcode.com/problems/random-pick-with-weight Medium
1332 String https://leetcode.com/problems/check-if-word-equals-summation-of-two-words Easy
1333 Math, String, Simulation https://leetcode.com/problems/fraction-addition-and-subtraction Medium
1334 Array, Dynamic Programming, Matrix https://leetcode.com/problems/number-of-paths-with-max-score Hard
1335 Array, Math, String, Backtracking https://leetcode.com/problems/verbal-arithmetic-puzzle Hard
String, Greedy, Binary Indexed Tree,
1336 Segment Tree https://leetcode.com/problems/minimum-possible-integer-after-at-most-k-adjacent-swaps-on-digits
Hard
1337 Math, Dynamic Programming https://leetcode.com/problems/number-of-sets-of-k-non-overlapping-line-segments
Medium
1338 Array, Graph, Topological Sort, Matrix https://leetcode.com/problems/strange-printer-ii Hard
Array, String, Divide and Conquer,
Sorting, Heap (Priority Queue),
1339 Quickselect https://leetcode.com/problems/find-the-kth-largest-integer-in-the-array Medium
1340 Array, Hash Table, String https://leetcode.com/problems/shortest-completing-word Easy
1341 Math https://leetcode.com/problems/count-odd-numbers-in-an-interval-range Easy
1342 Array, Hash Table, Two Pointers https://leetcode.com/problems/circular-array-loop Medium
1343 Array, Greedy, Sorting https://leetcode.com/problems/maximum-ice-cream-bars Medium
1344 Array, Sorting https://leetcode.com/problems/reduction-operations-to-make-the-array-elements-equal
Medium
1345 String, Dynamic Programming https://leetcode.com/problems/count-the-repetitions Hard
1346 Array, Math, Bit Manipulation, Matrix https://leetcode.com/problems/transform-to-chessboard Hard
1347 Array, Math, Two Pointers, Sorting https://leetcode.com/problems/moving-stones-until-consecutive-ii Medium
1348 String, Greedy https://leetcode.com/problems/maximum-binary-string-after-change Medium
1349 Array, String, Simulation https://leetcode.com/problems/final-value-of-variable-after-performing-operationsEasy
1350 Array, Math, Geometry https://leetcode.com/problems/minimum-area-rectangle-ii Medium
1351 String https://leetcode.com/problems/generate-a-string-with-characters-that-have-odd-counts
Easy
Hash Table, Math, Reservoir Sampling,
1352 Randomized https://leetcode.com/problems/random-flip-matrix Medium
1353 Math, Binary Search https://leetcode.com/problems/preimage-size-of-factorial-zeroes-function Hard
1354 Array, Greedy, Sorting https://leetcode.com/problems/eliminate-maximum-number-of-monsters Medium
1355 Array, Binary Search, Sorting https://leetcode.com/problems/find-target-indices-after-sorting-array Easy
1356 Math, Greedy, Game Theory https://leetcode.com/problems/sum-game Medium
1357 Hash Table, String https://leetcode.com/problems/number-of-different-integers-in-a-string Easy
Array, Hash Table, Binary Search,
1358 Design, Segment Tree https://leetcode.com/problems/range-frequency-queries Medium
1359 Hash Table, String, Counting https://leetcode.com/problems/sum-of-beauty-of-all-substrings Medium
Array, Tree, Depth-First Search, Binary
1360 Tree https://leetcode.com/problems/count-nodes-with-the-highest-score Medium
1361 String, Backtracking https://leetcode.com/problems/splitting-a-string-into-descending-consecutive-values
Medium
Array, Hash Table, Greedy, Sorting,
1362 Counting https://leetcode.com/problems/largest-values-from-labels Medium
1363 Hash Table, String https://leetcode.com/problems/can-convert-string-in-k-moves Medium
Array, Two Pointers, Binary Search,
1364 Sorting https://leetcode.com/problems/find-the-distance-value-between-two-arrays Easy
1365 Array, Math, Binary Search, Prefix Sum https://leetcode.com/problems/sum-of-floored-pairs Hard
1366 Dynamic Programming https://leetcode.com/problems/painting-a-grid-with-three-different-colors Hard
Array, Hash Table, String, Graph,
1367 Topological Sort https://leetcode.com/problems/find-all-possible-recipes-from-given-supplies Medium
Breadth-First Search, Graph, Shortest
1368 Path https://leetcode.com/problems/second-minimum-time-to-reach-destination Hard
1369 Array, Binary Search https://leetcode.com/problems/minimized-maximum-of-products-distributed-to-any-store
Medium
Array, Greedy, Heap (Priority Queue),
1370 Ordered Set https://leetcode.com/problems/find-servers-that-handled-most-number-of-requests
Hard
Dynamic Programming, Bit
1371 Manipulation, Memoization https://leetcode.com/problems/minimum-one-bit-operations-to-make-integers-zero
Hard
Dynamic Programming, Bit
Manipulation, Tree, Enumeration,
1372 Bitmask https://leetcode.com/problems/count-subtrees-with-max-distance-between-citiesHard
1373 Array, Simulation https://leetcode.com/problems/teemo-attacking Easy
1374 Array, Math, Bit Manipulation https://leetcode.com/problems/find-xor-sum-of-all-pairs-bitwise-and Hard
1375 https://leetcode.com/problems/maximum-employees-to-be-invited-to-a-meeting Hard
1376 String, Stack https://leetcode.com/problems/maximum-nesting-depth-of-two-valid-parentheses-strings
Medium
1377 Array, Prefix Sum https://leetcode.com/problems/find-the-middle-index-in-array Easy
Array, String, Binary Search, Prefix
1378 Sum https://leetcode.com/problems/plates-between-candles Medium
Array, Divide and Conquer, Bit
Manipulation, Heap (Priority Queue),
1379 Matrix, Prefix Sum, Quickselect https://leetcode.com/problems/find-kth-largest-xor-coordinate-value Medium
1380 Math, Recursion https://leetcode.com/problems/count-good-numbers Medium
1381 Array, Hash Table, String, Sorting https://leetcode.com/problems/invalid-transactions Medium
1382 String, Greedy https://leetcode.com/problems/minimum-time-to-type-word-using-special-typewriter
Easy
1383 Array, Hash Table, String https://leetcode.com/problems/evaluate-the-bracket-pairs-of-a-string Medium
Array, Depth-First Search, Breadth-
1384 First Search, Matrix https://leetcode.com/problems/find-all-groups-of-farmland Medium
String, Dynamic Programming, String
1385 Matching https://leetcode.com/problems/find-all-good-strings Hard
1386 Math, Binary Search https://leetcode.com/problems/smallest-good-base Hard
1387 Array, Greedy https://leetcode.com/problems/decrease-elements-to-make-array-zigzag Medium
Array, Binary Search, Bit Manipulation,
1388 Segment Tree https://leetcode.com/problems/find-a-value-of-a-mysterious-function-closest-to-target
Hard
1389 Array, Hash Table, Design https://leetcode.com/problems/finding-pairs-with-a-certain-sum Medium
1390 Math, Dynamic Programming https://leetcode.com/problems/least-operators-to-express-number Hard
1391 String, Greedy https://leetcode.com/problems/minimum-number-of-swaps-to-make-the-binary-string-alternating
Medium
1392 Array, Greedy https://leetcode.com/problems/merge-triplets-to-form-target-triplet Medium
Math, String, Dynamic Programming,
1393 Combinatorics https://leetcode.com/problems/vowels-of-all-substrings Medium
1394 String, Backtracking https://leetcode.com/problems/ambiguous-coordinates Medium
1395 Array, Prefix Sum https://leetcode.com/problems/describe-the-painting Medium
1396 Array, Bit Manipulation, Trie https://leetcode.com/problems/count-pairs-with-xor-in-a-range Hard
1397 Hash Table, String https://leetcode.com/problems/count-vowel-substrings-of-a-string Easy
1398 Array, Math, Dynamic Programming https://leetcode.com/problems/optimal-division Medium
1399 Array, Math https://leetcode.com/problems/find-greatest-common-divisor-of-array Easy
1400 Math https://leetcode.com/problems/sum-of-digits-in-base-k Easy
Hash Table, Design, Heap (Priority
1401 Queue), Data Stream, Ordered Set https://leetcode.com/problems/stock-price-fluctuation Medium
1402 Hash Table, Math https://leetcode.com/problems/count-largest-group Easy
1403 String https://leetcode.com/problems/longer-contiguous-segments-of-ones-than-zeros Easy
Math, Dynamic Programming,
1404 Probability and Statistics https://leetcode.com/problems/soup-servings Medium
1405 Hash Table, String, Counting https://leetcode.com/problems/check-if-all-characters-have-equal-number-of-occurrences
Easy
1406 Math https://leetcode.com/problems/convert-integer-to-the-sum-of-two-no-zero-integers
Easy
Array, Dynamic Programming, Bit
1407 Manipulation https://leetcode.com/problems/make-the-xor-of-all-segments-equal-to-zero Hard
Array, Math, Dynamic Programming,
1408 Prefix Sum, Game Theory https://leetcode.com/problems/stone-game-viii Hard
1409 Union Find, Graph https://leetcode.com/problems/process-restricted-friend-requests Hard
1410 Array, Math, Geometry https://leetcode.com/problems/self-crossing Hard
1411 Two Pointers, String https://leetcode.com/problems/minimum-length-of-string-after-deleting-similar-ends
Medium
Array, Binary Search, Rolling Hash,
1412 Suffix Array, Hash Function https://leetcode.com/problems/longest-common-subpath Hard
1413 Array, Heap (Priority Queue) https://leetcode.com/problems/remove-stones-to-minimize-the-total Medium
1414 Array, Math, Sorting, Matrix https://leetcode.com/problems/minimum-operations-to-make-a-uni-value-grid Medium
Dynamic Programming, Graph,
1415 Topological Sort https://leetcode.com/problems/parallel-courses-iii Hard
1416 Array, Greedy, Matrix https://leetcode.com/problems/maximum-matrix-sum Medium
Dynamic Programming, Tree, Depth-
1417 First Search, Union Find https://leetcode.com/problems/smallest-missing-genetic-value-in-each-subtree Hard
1418 Array https://leetcode.com/problems/sum-of-beauty-in-the-array Medium
1419 Array, Sorting https://leetcode.com/problems/mean-of-array-after-removing-some-elements Easy
1420 Array, Math https://leetcode.com/problems/maximum-building-height Hard
1421 Array, Math, Matrix https://leetcode.com/problems/magic-squares-in-grid Medium
1422 String https://leetcode.com/problems/rearrange-spaces-between-words Easy
1423 Array, Binary Search, Sorting https://leetcode.com/problems/most-beautiful-item-for-each-query Medium
1424 Math, Design, Segment Tree https://leetcode.com/problems/fancy-sequence Hard
1425 Design, Heap (Priority Queue) https://leetcode.com/problems/seat-reservation-manager Medium
1426 String https://leetcode.com/problems/student-attendance-record-i Easy
1427 String https://leetcode.com/problems/binary-string-with-substrings-representing-1-to-n Medium
1428 Array, Math, Counting, Number Theory https://leetcode.com/problems/number-of-different-subsequences-gcds Hard
1429 Hash Table, String, Counting https://leetcode.com/problems/redistribute-characters-to-make-all-strings-equal Easy
1430 Array https://leetcode.com/problems/watering-plants Medium
Array, Hash Table, Counting,
1431 Enumeration, Prefix Sum https://leetcode.com/problems/maximum-number-of-ways-to-partition-an-array Hard
1432 Array, Greedy https://leetcode.com/problems/two-furthest-houses-with-different-colors Easy
1433 Math https://leetcode.com/problems/prime-arrangements Easy
1434 Array https://leetcode.com/problems/find-nearest-point-that-has-the-same-x-or-y-coordinate
Easy
Math, Dynamic Programming, Tree,
Graph, Topological Sort,
1435 Combinatorics https://leetcode.com/problems/count-ways-to-build-rooms-in-an-ant-colony Hard
1436 Array, Math, Dynamic Programming https://leetcode.com/problems/number-of-smooth-descent-periods-of-a-stock Medium
1437 Array, Hash Table, String https://leetcode.com/problems/people-whose-list-of-favorite-companies-is-not-a-subset-of-another-list
Medium
1438 String, Dynamic Programming, Greedy https://leetcode.com/problems/minimum-number-of-buckets-required-to-collect-rainwater-from-houses
Medium
Array, Binary Search, Sorting, Prefix
1439 Sum https://leetcode.com/problems/minimum-space-wasted-from-packaging Hard
1440 Hash Table, Math https://leetcode.com/problems/powerful-integers Medium
1441 Array https://leetcode.com/problems/maximum-difference-between-increasing-elementsEasy
1442 Math, String https://leetcode.com/problems/day-of-the-year Easy
1443 Math, Backtracking, Bit Manipulation https://leetcode.com/problems/circular-permutation-in-binary-representation Medium
1444 Array, Math, Union Find, Sorting https://leetcode.com/problems/gcd-sort-of-an-array Hard
Array, Hash Table, Sorting, Heap
1445 (Priority Queue) https://leetcode.com/problems/find-subsequence-of-length-k-with-the-largest-sum
Easy
1446 Array, Hash Table, Math, Two Pointers https://leetcode.com/problems/number-of-ways-where-square-of-number-is-equal-to-product-of-two-numbers
Medium
1447 Math, Geometry https://leetcode.com/problems/circle-and-rectangle-overlapping Medium
Array, Dynamic Programming,
Segment Tree, Queue, Heap (Priority
1448 Queue), Monotonic Queue https://leetcode.com/problems/delivering-boxes-from-storage-to-ports Hard
1449 Hash Table, String https://leetcode.com/problems/maximum-number-of-words-you-can-type Easy
1450 Array, Greedy, Sorting https://leetcode.com/problems/array-with-elements-not-equal-to-average-of-neighbors
Medium
1451 Array, Hash Table, Bit Manipulation https://leetcode.com/problems/triples-with-bitwise-and-equal-to-zero Hard
1452 Array, String, Dynamic Programming https://leetcode.com/problems/number-of-ways-to-form-a-target-string-given-a-dictionary
Hard
1453 Array, Hash Table, Prefix Sum https://leetcode.com/problems/check-if-all-the-integers-in-a-range-are-covered Easy
1454 Array, Queue, Simulation https://leetcode.com/problems/time-needed-to-buy-tickets Easy
1455 String, Stack, Greedy https://leetcode.com/problems/check-if-a-parentheses-string-can-be-valid Medium
1456 Math https://leetcode.com/problems/day-of-the-week Easy
1457 Math https://leetcode.com/problems/simplified-fractions Medium
1458 Two Pointers, String https://leetcode.com/problems/reverse-prefix-of-word Easy
1459 Math, Geometry https://leetcode.com/problems/valid-boomerang Easy
1460 Array, Math, Number Theory https://leetcode.com/problems/check-if-it-is-a-good-array Hard
Math, Tree, Depth-First Search,
1461 Breadth-First Search https://leetcode.com/problems/tree-of-coprimes Hard
1462 String, Breadth-First Search https://leetcode.com/problems/lexicographically-smallest-string-after-applying-operations
Medium
1463 Bit Manipulation, Enumeration https://leetcode.com/problems/maximum-number-of-achievable-transfer-requestsHard
1464 String https://leetcode.com/problems/reformat-date Easy
1465 Hash Table, String https://leetcode.com/problems/second-largest-digit-in-a-string Easy
Hash Table, String, Counting, Prefix
1466 Sum https://leetcode.com/problems/change-minimum-characters-to-satisfy-one-of-three-conditions
Medium
1467 String, Greedy https://leetcode.com/problems/maximum-value-after-insertion Medium
1468 Array, Sorting https://leetcode.com/problems/minimum-difference-between-highest-and-lowest-of-k-scores
Easy
Array, Binary Search, Sliding Window,
1469 Prefix Sum https://leetcode.com/problems/maximum-fruits-harvested-after-at-most-k-steps Hard
Array, Depth-First Search, Breadth-
1470 First Search, Matrix, Simulation https://leetcode.com/problems/contain-virus Hard
1471 Array, Math https://leetcode.com/problems/adding-two-negabinary-numbers Medium
Array, Dynamic Programming, Bit
1472 Manipulation, Memoization, Bitmask https://leetcode.com/problems/maximum-number-of-groups-getting-fresh-donutsHard
Dynamic Programming, Bit
1473 Manipulation, Memoization, Bitmask https://leetcode.com/problems/maximize-grid-happiness Hard
1474 Array, Bit Manipulation, Trie https://leetcode.com/problems/maximum-genetic-difference-query Hard
1475 Math https://leetcode.com/problems/number-of-burgers-with-no-waste-of-ingredients Medium
1476 Array, Greedy https://leetcode.com/problems/removing-minimum-and-maximum-from-array Medium
Array, Dynamic Programming, Prefix
1477 Sum https://leetcode.com/problems/find-good-days-to-rob-the-bank Medium
1478 Math, Binary Search, Greedy https://leetcode.com/problems/building-boxes Hard
Array, Hash Table, Breadth-First
1479 Search, Sorting https://leetcode.com/problems/get-watched-videos-by-your-friends Medium
1480 Array, Sorting https://leetcode.com/problems/filter-restaurants-by-vegan-friendly-price-and-distance
Medium
Array, Math, Depth-First Search,
Breadth-First Search, Graph,
1481 Geometry https://leetcode.com/problems/detonate-the-maximum-bombs Medium
1482 Array, Two Pointers, String https://leetcode.com/problems/sentence-similarity-iii Medium
1483 String https://leetcode.com/problems/number-of-strings-that-appear-as-substrings-in-word
Easy
1484 Array, Hash Table https://leetcode.com/problems/two-out-of-three Easy
1485 Array, Breadth-First Search, Graph https://leetcode.com/problems/the-time-when-the-network-becomes-idle Medium
1486 Array, Binary Search https://leetcode.com/problems/kth-smallest-product-of-two-sorted-arrays Hard
Math, Dynamic Programming,
Backtracking, Combinatorics,
1487 Probability and Statistics https://leetcode.com/problems/probability-of-a-two-boxes-having-the-same-number-of-distinct-balls
Hard
1488 Two Pointers, Binary Search, Graph https://leetcode.com/problems/count-pairs-of-nodes Hard
1489 Array, Greedy, Matrix https://leetcode.com/problems/minimum-cost-homecoming-of-a-robot-in-a-grid Medium
Depth-First Search, Graph, Eulerian
1490 Circuit https://leetcode.com/problems/valid-arrangement-of-pairs Hard
Array, Binary Search, Simulation,
1491 Prefix Sum https://leetcode.com/problems/find-the-student-that-will-replace-the-chalk Medium
Array, Dynamic Programming,
Backtracking, Bit Manipulation,
1492 Bitmask https://leetcode.com/problems/distribute-repeating-integers Hard
1493 Array, Math, Simulation https://leetcode.com/problems/minimum-number-of-operations-to-reinitialize-a-permutation
Medium
1494 Array, Greedy https://leetcode.com/problems/add-minimum-number-of-rungs Medium
1495 Array, Breadth-First Search, Matrix https://leetcode.com/problems/minimum-moves-to-reach-target-with-rotations Hard
1496 String, Greedy https://leetcode.com/problems/latest-time-by-replacing-hidden-digits Easy
1497 String, Simulation https://leetcode.com/problems/sum-of-digits-of-string-after-convert Easy
1498 String https://leetcode.com/problems/reformat-phone-number Easy
Design, Queue, Heap (Priority Queue),
1499 Ordered Set https://leetcode.com/problems/finding-mk-average Hard
Hash Table, Binary Search, Tree,
1500 Depth-First Search, Binary Tree https://leetcode.com/problems/merge-bsts-to-create-single-bst Hard
1501 Array, Enumeration https://leetcode.com/problems/count-special-quadruplets Easy
Array, Hash Table, Math, Counting,
1502 Number Theory https://leetcode.com/problems/number-of-pairs-of-interchangeable-rectangles Medium
1503 Array, String https://leetcode.com/problems/number-of-pairs-of-strings-with-concatenation-equal-to-target
Medium
1504 Array, Math https://leetcode.com/problems/four-divisors Medium
1505 Array, Simulation https://leetcode.com/problems/most-visited-sector-in-a-circular-track Easy
1506 Array, Greedy, String Matching https://leetcode.com/problems/form-array-by-concatenating-subarrays-of-another-array
Medium
1507 Array, Dynamic Programming https://leetcode.com/problems/minimum-skips-to-arrive-at-meeting-on-time Hard
1508 Array, Math, Simulation https://leetcode.com/problems/find-missing-observations Medium
1509 Array, Backtracking, Graph https://leetcode.com/problems/maximum-path-quality-of-a-graph Hard
1510 Math https://leetcode.com/problems/three-divisors Easy
Array, Hash Table, String, Sorting,
1511 Ordered Set https://leetcode.com/problems/display-table-of-food-orders-in-a-restaurant Medium
1512 Math, Binary Search https://leetcode.com/problems/minimum-garden-perimeter-to-collect-enough-apples
Medium
1513 Array, Hash Table, Design, Counting https://leetcode.com/problems/detect-squares Medium
String, Dynamic Programming, Suffix
1514 Array https://leetcode.com/problems/number-of-ways-to-separate-numbers Hard
String, Stack, Greedy, Monotonic
1515 Stack https://leetcode.com/problems/smallest-k-length-subsequence-with-occurrences-of-a-letter
Hard
Array, Math, Dynamic Programming,
1516 Bit Manipulation, Bitmask https://leetcode.com/problems/the-number-of-good-subsets Hard
1517 Linked List https://leetcode.com/problems/find-the-minimum-and-maximum-number-of-nodes-between-critical-points
Medium
1518 Array, Sliding Window https://leetcode.com/problems/k-radius-subarray-averages Medium
1519 Array, Hash Table, String, Counting https://leetcode.com/problems/kth-distinct-string-in-an-array Easy
Array, Hash Table, Design, Data
1520 Stream https://leetcode.com/problems/design-an-ordered-stream Easy
1521 String https://leetcode.com/problems/delete-characters-to-make-fancy-string Easy
1522 Array, Matrix, Prefix Sum https://leetcode.com/problems/largest-magic-square Medium
Hash Table, Tree, Breadth-First
1523 Search, Design https://leetcode.com/problems/operations-on-tree Medium
1524 Array, Matrix, Simulation https://leetcode.com/problems/convert-1d-array-into-2d-array Easy
1525 Array, Sorting https://leetcode.com/problems/minimum-number-of-moves-to-seat-everyone Easy
1526 Two Pointers, String https://leetcode.com/problems/magical-string Medium
1527 Math, Stack, Simulation https://leetcode.com/problems/clumsy-factorial Medium
1528 Array, String https://leetcode.com/problems/check-if-string-is-a-prefix-of-array Easy
1529 Array, Greedy https://leetcode.com/problems/previous-permutation-with-one-swap Medium
Array, Binary Search, Greedy, Queue,
1530 Sorting, Monotonic Queue https://leetcode.com/problems/maximum-number-of-tasks-you-can-assign Hard
1531 Hash Table, String https://leetcode.com/problems/rings-and-rods Easy
1532 Array, Breadth-First Search https://leetcode.com/problems/maximum-candies-you-can-get-from-boxes Hard
Hash Table, Tree, Depth-First Search,
1533 Design https://leetcode.com/problems/throne-inheritance Medium
1534 Array, Backtracking, Bit Manipulation https://leetcode.com/problems/count-number-of-maximum-bitwise-or-subsets Medium
1535 Math, String https://leetcode.com/problems/number-of-days-between-two-dates Easy
1536 Math https://leetcode.com/problems/closest-divisors Medium
Array, Dynamic Programming, Bit
1537 Manipulation, Bitmask https://leetcode.com/problems/minimum-incompatibility Hard
1538 Array, Greedy, Sorting https://leetcode.com/problems/maximum-element-after-decreasing-and-rearranging
Medium
1539 Array, Divide and Conquer https://leetcode.com/problems/find-array-given-subset-sums Hard
1540 Array, String, Simulation https://leetcode.com/problems/adding-spaces-to-a-string Medium
1541 Array, Hash Table, String, Counting https://leetcode.com/problems/count-common-words-with-one-occurrence Easy
1542 Math, Geometry, Randomized https://leetcode.com/problems/best-position-for-a-service-centre Hard
1543 Graph https://leetcode.com/problems/minimum-degree-of-a-connected-trio-in-a-graph Hard
1544 Two Pointers, String https://leetcode.com/problems/remove-palindromic-subsequences Easy
1545 Dynamic Programming, Memoization https://leetcode.com/problems/the-earliest-and-latest-rounds-where-players-compete
Hard
String, Dynamic Programming, Trie,
Sliding Window, Rolling Hash, Hash
1546 Function https://leetcode.com/problems/distinct-echo-substrings Hard
Array, Hash Table, Sorting,
1547 Enumeration https://leetcode.com/problems/recover-the-original-array Hard
1548 Math, String, Greedy, Game Theory https://leetcode.com/problems/remove-colored-pieces-if-both-neighbors-are-the-same-color
Medium
1549 Array https://leetcode.com/problems/minimum-distance-to-the-target-element Easy
1550 String https://leetcode.com/problems/check-if-numbers-are-ascending-in-a-sentence Easy
1551 String, Greedy https://leetcode.com/problems/minimum-moves-to-convert-string Easy
1552 Array, Simulation https://leetcode.com/problems/count-unhappy-friends Medium
1553 Array, Two Pointers, String https://leetcode.com/problems/find-first-palindromic-string-in-the-array Easy
Array, Heap (Priority Queue),
1554 Simulation https://leetcode.com/problems/number-of-orders-in-the-backlog Medium
1555 Array, Matrix, Simulation https://leetcode.com/problems/cyclically-rotating-a-grid Medium
1556 String, Simulation https://leetcode.com/problems/execution-of-all-suffix-instructions-staying-in-a-grid
Medium
1557 String https://leetcode.com/problems/check-if-binary-string-has-at-most-one-segment-of-ones
Easy
1558 Array, Hash Table, String, Sorting https://leetcode.com/problems/alert-using-same-key-card-three-or-more-times-in-a-one-hour-period
Medium
Array, Hash Table, String, Trie, Hash
1559 Function https://leetcode.com/problems/delete-duplicate-folders-in-system Hard
String, Backtracking, Greedy,
1560 Counting, Enumeration https://leetcode.com/problems/longest-subsequence-repeated-k-times Hard
1561 Math, Brainteaser https://leetcode.com/problems/moving-stones-until-consecutive Medium
1562 Math, String https://leetcode.com/problems/the-number-of-full-rounds-you-have-played Medium
1563 Array, Sorting https://leetcode.com/problems/widest-vertical-area-between-two-points-containing-no-points
Medium
Math, String, Dynamic Programming,
1564 Stack https://leetcode.com/problems/minimum-cost-to-change-the-final-value-of-expression
Hard
1565 Math, Enumeration https://leetcode.com/problems/count-square-sum-triples Easy
1566 Array, Math, Dynamic Programming https://leetcode.com/problems/count-ways-to-make-array-with-product Hard
Array, Hash Table, Sorting,
1567 Enumeration https://leetcode.com/problems/finding-3-digit-even-numbers Easy
1568 Array, String https://leetcode.com/problems/maximum-number-of-words-found-in-sentences Easy
Math, Dynamic Programming, Breadth-
First Search, Graph, Memoization,
1569 Game Theory https://leetcode.com/problems/cat-and-mouse-ii Hard
Depth-First Search, Graph, Eulerian
1570 Circuit https://leetcode.com/problems/cracking-the-safe Hard
1571 Math, Greedy https://leetcode.com/problems/max-difference-you-can-get-from-changing-an-integer
Medium
1572 Math, Recursion https://leetcode.com/problems/maximize-number-of-nice-divisors Hard
1573 Array, Greedy https://leetcode.com/problems/minimum-elements-to-add-to-form-a-given-sum Medium
1574 Array, Dynamic Programming, Matrix https://leetcode.com/problems/count-fertile-pyramids-in-a-land Hard
1575 Hash Table, String https://leetcode.com/problems/html-entity-parser Medium
1576 Hash Table, Design https://leetcode.com/problems/design-authentication-manager Medium
Array, Hash Table, Design, Heap
1577 (Priority Queue), Ordered Set https://leetcode.com/problems/design-movie-rental-system Hard
1578 Hash Table, String, Counting https://leetcode.com/problems/check-whether-two-strings-are-almost-equivalent Easy
1579 String, Stack https://leetcode.com/problems/tag-validator Hard
1580 Divide and Conquer, Tree https://leetcode.com/problems/logical-or-of-two-binary-grids-represented-as-quad-trees
Medium
Tree, Depth-First Search, Breadth-First
1581 Search, Binary Tree https://leetcode.com/problems/print-binary-tree Medium
1582 Array, String, Greedy https://leetcode.com/problems/largest-number-after-mutating-substring Medium
1583 Array, Greedy https://leetcode.com/problems/minimum-number-of-people-to-teach Medium
Array, Math, Sorting, Heap (Priority
1584 Queue), Matrix, Prefix Sum https://leetcode.com/problems/get-biggest-three-rhombus-sums-in-a-grid Medium
1585 Simulation https://leetcode.com/problems/incremental-memory-leak Medium
1586 String, Simulation https://leetcode.com/problems/decode-the-slanted-ciphertext Medium
Array, Math, Greedy, Counting, Game
1587 Theory https://leetcode.com/problems/stone-game-ix Medium
1588 Array, Matrix, Enumeration https://leetcode.com/problems/check-if-word-can-be-placed-in-crossword Medium
Array, Math, String, Dynamic
1589 Programming, Stack, Memoization https://leetcode.com/problems/the-score-of-students-solving-math-expression Hard
1590 Math https://leetcode.com/problems/a-number-after-a-double-reversal Easy
1591 Math https://leetcode.com/problems/largest-palindrome-product Hard
Array, Math, Bit Manipulation,
1592 Brainteaser, Game Theory https://leetcode.com/problems/chalkboard-xor-game Hard
1593 Math, String, Combinatorics https://leetcode.com/problems/minimum-number-of-operations-to-make-string-sorted
Hard
1594 String https://leetcode.com/problems/masking-personal-information Medium
Hash Table, Math, String, Stack,
1595 Recursion https://leetcode.com/problems/basic-calculator-iv Hard
1596 Linked List https://leetcode.com/problems/reverse-nodes-in-even-length-groups Medium
1597 Array, Math, Geometry https://leetcode.com/problems/maximum-number-of-darts-inside-of-a-circular-dartboard
Hard
1598 Array, Hash Table, Design https://leetcode.com/problems/apply-discount-every-n-orders Medium
1599 Tree, Graph, Topological Sort https://leetcode.com/problems/number-of-ways-to-reconstruct-a-tree Hard
1600 String, Dynamic Programming https://leetcode.com/problems/check-if-an-original-string-exists-given-two-encoded-strings
Hard
1601 String, Rolling Hash, Hash Function https://leetcode.com/problems/maximum-product-of-the-length-of-two-palindromic-substrings
Hard
1602 Array, Hash Table https://leetcode.com/problems/card-flipping-game Medium
1603 Design, Simulation https://leetcode.com/problems/walking-robot-simulation-ii Medium
1604 https://leetcode.com/problems/destroying-asteroids Medium
1605 https://leetcode.com/problems/number-of-laser-beams-in-a-bank Medium
1606 Math, Greedy, Recursion https://leetcode.com/problems/minimum-non-zero-product-of-the-array-elementsMedium
Hash Table, Binary Search, Design,
1607 Sorting, Ordered Set https://leetcode.com/problems/tweet-counts-per-frequency Medium
Design, Heap (Priority Queue), Data
1608 Stream, Ordered Set https://leetcode.com/problems/sequentially-ordinal-rank-tracker Hard
1609 Array https://leetcode.com/problems/smallest-index-with-equal-value Easy
1610 Math, String, Simulation https://leetcode.com/problems/fizz-buzz Easy
1611 Math, Backtracking, Enumeration https://leetcode.com/problems/next-greater-numerically-balanced-number Medium
1612 Array, Hash Table, Design, Simulation https://leetcode.com/problems/simple-bank-system Medium
1613 String https://leetcode.com/problems/number-of-valid-words-in-a-sentence Easy
1614 https://leetcode.com/problems/check-if-all-as-appears-before-all-bs Easy
1615 Array, Two Pointers, Simulation https://leetcode.com/problems/watering-plants-ii Medium
1616 Array, Prefix Sum https://leetcode.com/problems/can-you-eat-your-favorite-candy-on-your-favorite-day
Medium
1617 Array, Matrix, Enumeration https://leetcode.com/problems/check-if-move-is-legal Medium
1618 Math, Enumeration https://leetcode.com/problems/sum-of-k-mirror-numbers Hard
1619 Math, String https://leetcode.com/problems/equal-rational-numbers Hard
1620 Array, Matrix https://leetcode.com/problems/image-overlap Medium
1621 Array, Simulation https://leetcode.com/problems/maximum-profit-of-operating-a-centennial-wheel Medium
1622 Array, Enumeration https://leetcode.com/problems/coordinate-with-maximum-network-quality Medium
1623 Array, Math https://leetcode.com/problems/escape-the-ghosts Medium
1624 Math https://leetcode.com/problems/abbreviating-the-product-of-a-range Hard
1625 Array, Simulation https://leetcode.com/problems/walking-robot-simulation Medium
Math, Two Pointers, Probability and
1626 Statistics https://leetcode.com/problems/statistics-from-a-large-sample Medium
1627 Array, String, Backtracking, Simulation https://leetcode.com/problems/number-of-valid-move-combinations-on-chessboard
Hard
Math, Bit Manipulation, Depth-First
1628 Search, Breadth-First Search https://leetcode.com/problems/bulb-switcher-ii Medium
 Crack The Coding Interview - Dinesh Varyani
https://www.youtube.com/user/hubberspot?sub_confirmation=1

# Topic Question Difficulty

1 Array, Hash Table https://leetcode.com/problems/two-sum Easy

Array, Divide and Conquer, Dynamic
2 Programming https://leetcode.com/problems/maximum-subarray Easy
3 Array, Dynamic Programming https://leetcode.com/problems/best-time-to-buy-and-sell-stock Easy
4 String, Stack https://leetcode.com/problems/valid-parentheses Easy
5 Linked List, Recursion https://leetcode.com/problems/reverse-linked-list Easy
6 Linked List, Recursion https://leetcode.com/problems/merge-two-sorted-lists Easy
Math, Dynamic Programming,
7 Memoization https://leetcode.com/problems/climbing-stairs Easy
Tree, Depth-First Search, Breadth-First
8 Search, Binary Tree https://leetcode.com/problems/symmetric-tree Easy
9 Array, Bit Manipulation https://leetcode.com/problems/single-number Easy
10 Array, Two Pointers https://leetcode.com/problems/move-zeroes Easy
11 Hash Table, Linked List, Two Pointers https://leetcode.com/problems/intersection-of-two-linked-lists Easy
Array, Hash Table, Divide and
12 Conquer, Sorting, Counting https://leetcode.com/problems/majority-element Easy
Linked List, Two Pointers, Stack,
13 Recursion https://leetcode.com/problems/palindrome-linked-list Easy
Tree, Depth-First Search, Breadth-First
14 Search, Binary Tree https://leetcode.com/problems/invert-binary-tree Easy
15 Stack, Design https://leetcode.com/problems/min-stack Easy
16 Tree, Depth-First Search, Binary Tree https://leetcode.com/problems/diameter-of-binary-tree Easy
Stack, Tree, Depth-First Search, Binary
17 Tree https://leetcode.com/problems/binary-tree-inorder-traversal Easy
18 Hash Table, Linked List, Two Pointers https://leetcode.com/problems/linked-list-cycle Easy
19 String https://leetcode.com/problems/longest-common-prefix Easy
20 Array, Binary Search https://leetcode.com/problems/search-insert-position Easy
21 Array, Hash Table https://leetcode.com/problems/find-all-numbers-disappeared-in-an-array Easy
Tree, Depth-First Search, Breadth-First
22 Search, Binary Tree https://leetcode.com/problems/merge-two-binary-trees Easy
Tree, Depth-First Search, Breadth-First
23 Search, Binary Tree https://leetcode.com/problems/maximum-depth-of-binary-tree Easy
Array, Divide and Conquer, Tree,
24 Binary Search Tree, Binary Tree https://leetcode.com/problems/convert-sorted-array-to-binary-search-tree Easy
25 Array, Two Pointers https://leetcode.com/problems/remove-duplicates-from-sorted-array Easy
Dynamic Programming, Bit
26 Manipulation https://leetcode.com/problems/counting-bits Easy
27 Array, Dynamic Programming https://leetcode.com/problems/min-cost-climbing-stairs Easy
28 Tree, Depth-First Search, Binary Tree https://leetcode.com/problems/balanced-binary-tree Easy
29 Math https://leetcode.com/problems/palindrome-number Easy
Tree, Depth-First Search, Breadth-First
30 Search, Binary Tree https://leetcode.com/problems/same-tree Easy
Tree, Depth-First Search, Binary
31 Search Tree, Binary Tree https://leetcode.com/problems/lowest-common-ancestor-of-a-binary-search-tree Easy
32 Tree, Depth-First Search, Binary Tree https://leetcode.com/problems/path-sum Easy
Tree, Depth-First Search, String
33 Matching, Binary Tree, Hash Function https://leetcode.com/problems/subtree-of-another-tree Easy
Array, Hash Table, Math, Bit
34 Manipulation, Sorting https://leetcode.com/problems/missing-number Easy
35 Array, Dynamic Programming https://leetcode.com/problems/pascals-triangle Easy
36 Hash Table, Math, Two Pointers https://leetcode.com/problems/happy-number Easy
37 Linked List, Two Pointers https://leetcode.com/problems/middle-of-the-linked-list Easy
38 Array, Two Pointers, Binary Search https://leetcode.com/problems/two-sum-ii-input-array-is-sorted Easy
39 Hash Table, String, Queue, Counting https://leetcode.com/problems/first-unique-character-in-a-string Easy
40 Array, Two Pointers, Sorting https://leetcode.com/problems/squares-of-a-sorted-array Easy
41 Linked List, Recursion https://leetcode.com/problems/remove-linked-list-elements Easy
Array, Depth-First Search, Breadth-
42 First Search, Matrix https://leetcode.com/problems/island-perimeter Easy
43 Linked List https://leetcode.com/problems/remove-duplicates-from-sorted-list Easy
Math, String, Bit Manipulation,
44 Simulation https://leetcode.com/problems/add-binary Easy
45 Hash Table, String, Sorting https://leetcode.com/problems/valid-anagram Easy
46 Binary Search, Interactive https://leetcode.com/problems/first-bad-version Easy
47 Two Pointers, String, Greedy https://leetcode.com/problems/valid-palindrome-ii Easy
48 Linked List https://leetcode.com/problems/delete-node-in-a-linked-list Easy
Array, Hash Table, Two Pointers,
49 Binary Search, Sorting https://leetcode.com/problems/intersection-of-two-arrays-ii Easy
50 Two Pointers, String, Recursion https://leetcode.com/problems/reverse-string Easy
 Tree, Depth-First Search, Binary
51 Search Tree, Binary Tree https://leetcode.com/problems/range-sum-of-bst Easy
Stack, Tree, Depth-First Search, Binary
52 Tree https://leetcode.com/problems/binary-tree-postorder-traversal Easy
Two Pointers, String, Dynamic
53 Programming https://leetcode.com/problems/is-subsequence Easy
String, Tree, Depth-First Search,
54 Binary Tree https://leetcode.com/problems/binary-tree-paths Easy
Tree, Depth-First Search, Breadth-First
55 Search, Binary Tree https://leetcode.com/problems/minimum-depth-of-binary-tree Easy
Stack, Tree, Depth-First Search, Binary
56 Tree https://leetcode.com/problems/binary-tree-preorder-traversal Easy
57 Array, Math https://leetcode.com/problems/plus-one Easy
Two Pointers, String, Stack,
58 Simulation https://leetcode.com/problems/backspace-string-compare Easy
59 Two Pointers, String, String Matching https://leetcode.com/problems/implement-strstr Easy
60 Array, Hash Table, Sorting https://leetcode.com/problems/contains-duplicate Easy
61 Hash Table, String https://leetcode.com/problems/jewels-and-stones Easy
Array, Depth-First Search, Breadth-
62 First Search, Matrix https://leetcode.com/problems/flood-fill Easy
Hash Table, Two Pointers, Tree, Depth-
First Search, Breadth-First Search,
63 Binary Search Tree, Binary Tree https://leetcode.com/problems/two-sum-iv-input-is-a-bst Easy
64 Math, Binary Search https://leetcode.com/problems/sqrtx Easy
65 Hash Table, String https://leetcode.com/problems/isomorphic-strings Easy
66 Array, Binary Search https://leetcode.com/problems/binary-search Easy
67 String, String Matching https://leetcode.com/problems/repeated-substring-pattern Easy
68 Array, Two Pointers https://leetcode.com/problems/remove-element Easy
Tree, Depth-First Search, Breadth-First
69 Search, Binary Tree https://leetcode.com/problems/sum-of-left-leaves Easy
70 Bit Manipulation https://leetcode.com/problems/hamming-distance Easy
71 Two Pointers, String https://leetcode.com/problems/valid-palindrome Easy
72 Math, String, Simulation https://leetcode.com/problems/add-strings Easy
73 Stack, Design, Queue https://leetcode.com/problems/implement-queue-using-stacks Easy
74 Hash Table, Math, String https://leetcode.com/problems/roman-to-integer Easy
75 Array, Hash Table, Graph https://leetcode.com/problems/find-the-town-judge Easy
76 Array, Two Pointers, Sorting https://leetcode.com/problems/merge-sorted-array Easy
77 String, Stack https://leetcode.com/problems/remove-all-adjacent-duplicates-in-string Easy
Tree, Depth-First Search, Breadth-First
78 Search, Binary Tree https://leetcode.com/problems/average-of-levels-in-binary-tree Easy
79 Array, Prefix Sum https://leetcode.com/problems/find-pivot-index Easy
80 Array, Hash Table, Sorting, Counting https://leetcode.com/problems/how-many-numbers-are-smaller-than-the-current-number
Easy
81 Math, Bit Manipulation, Recursion https://leetcode.com/problems/power-of-two Easy
Math, Dynamic Programming,
82 Recursion, Memoization https://leetcode.com/problems/fibonacci-number Easy
83 Divide and Conquer, Bit Manipulation https://leetcode.com/problems/reverse-bits Easy
84 Hash Table, String https://leetcode.com/problems/word-pattern Easy
85 Array, Hash Table, String https://leetcode.com/problems/verifying-an-alien-dictionary Easy
Tree, Depth-First Search, Breadth-First
86 Search, Binary Tree https://leetcode.com/problems/cousins-in-binary-tree Easy
87 Two Pointers, String https://leetcode.com/problems/count-binary-substrings Easy
88 Array, Two Pointers, Sorting https://leetcode.com/problems/sort-array-by-parity Easy
89 Bit Manipulation https://leetcode.com/problems/number-of-1-bits Easy
90 Array, Math, Sorting https://leetcode.com/problems/maximum-product-of-three-numbers Easy
91 Math, String https://leetcode.com/problems/excel-sheet-column-title Easy
Array, Hash Table, Two Pointers,
92 Binary Search, Sorting https://leetcode.com/problems/intersection-of-two-arrays Easy
93 Hash Table, String, Greedy https://leetcode.com/problems/longest-palindrome Easy
94 Tree, Binary Search Tree, Binary Tree https://leetcode.com/problems/search-in-a-binary-search-tree Easy
95 Two Pointers, String https://leetcode.com/problems/reverse-words-in-a-string-iii Easy
96 Math, String https://leetcode.com/problems/excel-sheet-column-number Easy
Array, Hash Table, Linked List, Design,
97 Hash Function https://leetcode.com/problems/design-hashmap Easy
98 Linked List, Math https://leetcode.com/problems/convert-binary-number-in-a-linked-list-to-integer Easy
99 Array https://leetcode.com/problems/max-consecutive-ones Easy
100 Array, Prefix Sum https://leetcode.com/problems/running-sum-of-1d-array Easy
101 Array, Dynamic Programming https://leetcode.com/problems/pascals-triangle-ii Easy
Stack, Tree, Depth-First Search, Binary
102 Search Tree, Binary Tree https://leetcode.com/problems/increasing-order-search-tree Easy
103 Array, Hash Table, String https://leetcode.com/problems/find-common-characters Easy
104 Array, Two Pointers, String https://leetcode.com/problems/shortest-distance-to-a-character Easy
105 Array, Greedy https://leetcode.com/problems/can-place-flowers Easy
106 Array, Hash Table, Sliding Window https://leetcode.com/problems/contains-duplicate-ii Easy
107 Array, Hash Table, Math, Counting https://leetcode.com/problems/number-of-good-pairs Easy
108 Array https://leetcode.com/problems/shuffle-the-array Easy
109 Array, Binary Search https://leetcode.com/problems/kth-missing-positive-number Easy
110 Array, Binary Search https://leetcode.com/problems/peak-index-in-a-mountain-array Easy
Tree, Depth-First Search, Binary
111 Search Tree, Binary Tree https://leetcode.com/problems/find-mode-in-binary-search-tree Easy
112 Array, Heap (Priority Queue) https://leetcode.com/problems/last-stone-weight Easy
113 Bit Manipulation https://leetcode.com/problems/number-complement Easy
114 Math, Binary Search https://leetcode.com/problems/valid-perfect-square Easy
115 Math, Binary Search https://leetcode.com/problems/arranging-coins Easy
Array, Two Pointers, Matrix,
116 Simulation https://leetcode.com/problems/flipping-an-image Easy
Tree, Design, Binary Search Tree,
Heap (Priority Queue), Binary Tree,
117 Data Stream https://leetcode.com/problems/kth-largest-element-in-a-stream Easy
Tree, Depth-First Search, Breadth-First
118 Search https://leetcode.com/problems/maximum-depth-of-n-ary-tree Easy
119 Array, Hash Table https://leetcode.com/problems/degree-of-an-array Easy
Hash Table, String, Bit Manipulation,
120 Sorting https://leetcode.com/problems/find-the-difference Easy
Tree, Depth-First Search, Breadth-First
Search, Binary Search Tree, Binary
121 Tree https://leetcode.com/problems/minimum-absolute-difference-in-bst Easy
122 Array, Binary Search, Matrix https://leetcode.com/problems/count-negative-numbers-in-a-sorted-matrix Easy
123 Array, Matrix, Simulation https://leetcode.com/problems/reshape-the-matrix Easy
124 Array, Matrix https://leetcode.com/problems/toeplitz-matrix Easy
125 Array, Design, Prefix Sum https://leetcode.com/problems/range-sum-query-immutable Easy
126 Stack, Design, Queue https://leetcode.com/problems/implement-stack-using-queues Easy
Array, Hash Table, Stack, Monotonic
127 Stack https://leetcode.com/problems/next-greater-element-i Easy
128 Tree, Depth-First Search, Binary Tree https://leetcode.com/problems/sum-of-root-to-leaf-binary-numbers Easy
Array, Hash Table, Bit Manipulation,
129 Sorting https://leetcode.com/problems/set-mismatch Easy
130 String, String Matching https://leetcode.com/problems/rotate-string Easy
131 Array, Hash Table, String https://leetcode.com/problems/unique-email-addresses Easy
132 Array, Two Pointers, Sorting https://leetcode.com/problems/sort-array-by-parity-ii Easy
133 String, Simulation https://leetcode.com/problems/robot-return-to-origin Easy
134 Array https://leetcode.com/problems/longest-continuous-increasing-subsequence Easy
135 String, Greedy, Counting https://leetcode.com/problems/split-a-string-in-balanced-strings Easy
136 Math, Simulation, Number Theory https://leetcode.com/problems/add-digits Easy
Array, Math, Two Pointers, String,
137 Greedy https://leetcode.com/problems/di-string-match Easy
138 Tree, Depth-First Search, Binary Tree https://leetcode.com/problems/leaf-similar-trees Easy
139 Array, Math, Prefix Sum https://leetcode.com/problems/sum-of-all-odd-length-subarrays Easy
140 Array, String, Sorting https://leetcode.com/problems/reorder-data-in-log-files Easy
Array, Hash Table, Sorting, Counting
141 Sort https://leetcode.com/problems/relative-sort-array Easy
142 Tree, Depth-First Search, Binary Tree https://leetcode.com/problems/binary-tree-tilt Easy
143 Stack, Tree, Depth-First Search https://leetcode.com/problems/n-ary-tree-preorder-traversal Easy
144 Array, Sorting https://leetcode.com/problems/third-maximum-number Easy
Tree, Depth-First Search, Breadth-First
Search, Binary Search Tree, Binary
145 Tree https://leetcode.com/problems/minimum-distance-between-bst-nodes Easy
146 Array, Hash Table, Sorting https://leetcode.com/problems/longest-harmonious-subsequence Easy
147 Two Pointers, String https://leetcode.com/problems/long-pressed-name Easy
148 Array, Two Pointers https://leetcode.com/problems/duplicate-zeros Easy
149 Hash Table, String, Counting https://leetcode.com/problems/ransom-note Easy
150 Stack, Tree, Depth-First Search https://leetcode.com/problems/n-ary-tree-postorder-traversal Easy
151 Two Pointers, String https://leetcode.com/problems/reverse-vowels-of-a-string Easy
152 Array, Sliding Window https://leetcode.com/problems/maximum-average-subarray-i Easy
153 Math, Bit Manipulation https://leetcode.com/problems/number-of-steps-to-reduce-a-number-to-zero Easy
Math, Dynamic Programming,
154 Memoization https://leetcode.com/problems/n-th-tribonacci-number Easy
Array, Binary Search, Sorting, Heap
155 (Priority Queue), Matrix https://leetcode.com/problems/the-k-weakest-rows-in-a-matrix Easy
156 Array https://leetcode.com/problems/valid-mountain-array Easy
157 Two Pointers, String https://leetcode.com/problems/reverse-only-letters Easy
158 Array https://leetcode.com/problems/monotonic-array Easy
159 Array, Sorting https://leetcode.com/problems/minimum-absolute-difference Easy
160 Array https://leetcode.com/problems/summary-ranges Easy
161 Array, Math, Greedy https://leetcode.com/problems/minimum-cost-to-move-chips-to-the-same-position
Easy
162 Math, Geometry https://leetcode.com/problems/rectangle-overlap Easy
163 Hash Table, String https://leetcode.com/problems/buddy-strings Easy
164 Array https://leetcode.com/problems/kids-with-the-greatest-number-of-candies Easy
165 Math, Bit Manipulation, Recursion https://leetcode.com/problems/power-of-four Easy
166 Array, Greedy, Sorting https://leetcode.com/problems/maximum-units-on-a-truck Easy
String, Tree, Depth-First Search,
167 Binary Tree https://leetcode.com/problems/construct-string-from-binary-tree Easy
168 Array, Greedy, Sorting https://leetcode.com/problems/assign-cookies Easy
169 Array, Binary Search https://leetcode.com/problems/find-smallest-letter-greater-than-target Easy
170 Hash Table, String https://leetcode.com/problems/most-common-word Easy
171 Math https://leetcode.com/problems/ugly-number Easy
172 String https://leetcode.com/problems/consecutive-characters Easy
Tree, Depth-First Search, Breadth-First
173 Search, Binary Tree https://leetcode.com/problems/univalued-binary-tree Easy
Math, Dynamic Programming,
174 Brainteaser, Game Theory https://leetcode.com/problems/divisor-game Easy
175 Array, Hash Table, String https://leetcode.com/problems/unique-morse-code-words Easy
176 String, Stack https://leetcode.com/problems/remove-outermost-parentheses Easy
177 Math, String https://leetcode.com/problems/greatest-common-divisor-of-strings Easy
Array, Hash Table, Math, Counting,
178 Number Theory https://leetcode.com/problems/x-of-a-kind-in-a-deck-of-cards Easy
179 Array, Hash Table https://leetcode.com/problems/unique-number-of-occurrences Easy
180 Array, String https://leetcode.com/problems/shuffle-string Easy
181 Array, Math, Geometry https://leetcode.com/problems/minimum-time-visiting-all-points Easy
Array, Hash Table, Binary Search,
182 Sorting https://leetcode.com/problems/fair-candy-swap Easy
Array, Hash Table, Linked List, Design,
183 Hash Function https://leetcode.com/problems/design-hashset Easy
184 Array, Greedy https://leetcode.com/problems/lemonade-change Easy
185 Tree, Depth-First Search, Binary Tree https://leetcode.com/problems/second-minimum-node-in-a-binary-tree Easy
186 Array https://leetcode.com/problems/replace-elements-with-greatest-element-on-right-side
Easy
187 Math https://leetcode.com/problems/self-dividing-numbers Easy
188 Array, Hash Table, String https://leetcode.com/problems/minimum-index-sum-of-two-lists Easy
189 Array https://leetcode.com/problems/find-numbers-with-even-number-of-digits Easy
190 Array, Hash Table, Sorting https://leetcode.com/problems/sort-array-by-increasing-frequency Easy
191 Array, Matrix https://leetcode.com/problems/richest-customer-wealth Easy
192 String https://leetcode.com/problems/detect-capital Easy
193 Array, Matrix, Simulation https://leetcode.com/problems/transpose-matrix Easy
194 Array, Greedy https://leetcode.com/problems/partition-array-into-three-parts-with-equal-sum Easy
195 Math, Brainteaser, Game Theory https://leetcode.com/problems/nim-game Easy
196 Array, Math https://leetcode.com/problems/add-to-array-form-of-integer Easy
197 String https://leetcode.com/problems/defanging-an-ip-address Easy
198 Array, Prefix Sum https://leetcode.com/problems/minimum-value-to-get-positive-step-by-step-sum Easy
199 Array, Stack, Simulation https://leetcode.com/problems/baseball-game Easy
200 String https://leetcode.com/problems/to-lower-case Easy
201 Hash Table, String, Counting https://leetcode.com/problems/maximum-number-of-balloons Easy
202 Array, Math https://leetcode.com/problems/find-n-unique-integers-sum-up-to-zero Easy
203 Backtracking, Bit Manipulation https://leetcode.com/problems/binary-watch Easy
204 Array, Hash Table https://leetcode.com/problems/distribute-candies Easy
205 Array, Hash Table, String https://leetcode.com/problems/find-words-that-can-be-formed-by-characters Easy
206 Math, Greedy https://leetcode.com/problems/maximum-69-number Easy
207 Hash Table, String https://leetcode.com/problems/destination-city Easy
208 Math https://leetcode.com/problems/subtract-the-product-and-sum-of-digits-of-an-integer
Easy
209 Array, Simulation https://leetcode.com/problems/create-target-array-in-the-given-order Easy
210 Array, Stack, Monotonic Stack https://leetcode.com/problems/final-prices-with-a-special-discount-in-a-shop Easy
211 Array, Greedy, Sorting https://leetcode.com/problems/maximize-sum-of-array-after-k-negations Easy
212 Hash Table, String https://leetcode.com/problems/uncommon-words-from-two-sentences Easy
213 Bit Manipulation https://leetcode.com/problems/binary-number-with-alternating-bits Easy
214 Array, Matrix https://leetcode.com/problems/matrix-diagonal-sum Easy
215 Array, Hash Table, String https://leetcode.com/problems/keyboard-row Easy
216 Array, Hash Table https://leetcode.com/problems/n-repeated-element-in-size-2n-array Easy
217 Two Pointers, String https://leetcode.com/problems/reverse-string-ii Easy
218 Math, Bit Manipulation https://leetcode.com/problems/convert-a-number-to-hexadecimal Easy
Array, Bit Manipulation, Sorting,
219 Counting https://leetcode.com/problems/sort-integers-by-the-number-of-1-bits Easy
220 Array, Math, Greedy, Sorting https://leetcode.com/problems/largest-perimeter-triangle Easy
221 Array, Matrix https://leetcode.com/problems/lucky-numbers-in-a-matrix Easy
222 Array, Hash Table, Sorting https://leetcode.com/problems/rank-transform-of-an-array Easy
223 String https://leetcode.com/problems/decrypt-string-from-alphabet-to-integer-mapping Easy
224 Array, Simulation https://leetcode.com/problems/build-array-from-permutation Easy
225 Array, Sorting, Heap (Priority Queue) https://leetcode.com/problems/maximum-product-of-two-elements-in-an-array Easy
226 Array, Math, Geometry https://leetcode.com/problems/check-if-it-is-a-straight-line Easy
227 String https://leetcode.com/problems/license-key-formatting Easy
228 Design, Queue, Data Stream https://leetcode.com/problems/number-of-recent-calls Easy
229 Math, Bit Manipulation https://leetcode.com/problems/xor-operation-in-an-array Easy
230 Array, Hash Table, Matrix, Simulation https://leetcode.com/problems/find-winner-on-a-tic-tac-toe-game Easy
231 Bit Manipulation https://leetcode.com/problems/complement-of-base-10-integer Easy
Array, Hash Table, Two Pointers,
232 Binary Search, Sorting https://leetcode.com/problems/check-if-n-and-its-double-exist Easy
233 String, Stack https://leetcode.com/problems/maximum-nesting-depth-of-the-parentheses Easy
234 String, Sorting https://leetcode.com/problems/sorting-the-sentence Easy
Array, Hash Table, String, Bit
235 Manipulation https://leetcode.com/problems/count-the-number-of-consistent-strings Easy
236 Math, Simulation https://leetcode.com/problems/distribute-candies-to-people Easy
237 Math, Recursion https://leetcode.com/problems/power-of-three Easy
238 Array https://leetcode.com/problems/1-bit-and-2-bit-characters Easy
239 Array https://leetcode.com/problems/decompress-run-length-encoded-list Easy
240 String https://leetcode.com/problems/goat-latin Easy
241 Array, Math, Simulation https://leetcode.com/problems/cells-with-odd-values-in-a-matrix Easy
242 Array, String https://leetcode.com/problems/count-items-matching-a-rule Easy
243 Array, Prefix Sum https://leetcode.com/problems/find-the-highest-altitude Easy
244 String, Stack https://leetcode.com/problems/make-the-string-great Easy
245 Array, String https://leetcode.com/problems/check-if-two-string-arrays-are-equivalent Easy
246 Array, Stack, Queue, Simulation https://leetcode.com/problems/number-of-students-unable-to-eat-lunch Easy
247 Math, Simulation https://leetcode.com/problems/water-bottles Easy
248 Array, Hash Table https://leetcode.com/problems/check-array-formation-through-concatenation Easy
249 Array, Greedy, Sorting, Counting Sort https://leetcode.com/problems/array-partition-i Easy
250 Array https://leetcode.com/problems/concatenation-of-array Easy
251 Array, Hash Table, Sorting https://leetcode.com/problems/make-two-arrays-equal-by-reversing-sub-arrays Easy
252 Array, Math https://leetcode.com/problems/range-addition-ii Easy
253 Array, Hash Table, Counting https://leetcode.com/problems/sum-of-unique-elements Easy
254 Array https://leetcode.com/problems/element-appearing-more-than-25-in-sorted-array Easy
255 Array, Sorting https://leetcode.com/problems/largest-number-at-least-twice-of-others Easy
256 String https://leetcode.com/problems/positions-of-large-groups Easy
Array, Math, Backtracking, Bit
257 Manipulation, Combinatorics https://leetcode.com/problems/sum-of-all-subset-xor-totals Easy
258 Array, Bit Manipulation https://leetcode.com/problems/decode-xored-array Easy
259 Array, Binary Search, Sorting https://leetcode.com/problems/special-array-with-x-elements-greater-than-or-equal-x
Easy
260 String https://leetcode.com/problems/longest-uncommon-subsequence-i Easy
261 Array, Hash Table, Counting https://leetcode.com/problems/find-lucky-integer-in-an-array Easy
262 Hash Table, String https://leetcode.com/problems/check-if-the-sentence-is-pangram Easy
263 String https://leetcode.com/problems/goal-parser-interpretation Easy
264 Design, Simulation, Counting https://leetcode.com/problems/design-parking-system Easy
Depth-First Search, Breadth-First
265 Search, Graph https://leetcode.com/problems/find-if-path-exists-in-graph Easy
266 Array https://leetcode.com/problems/number-of-students-doing-homework-at-a-given-timeEasy
267 Array, Sorting https://leetcode.com/problems/can-make-arithmetic-progression-from-sequence Easy
268 Math, Simulation https://leetcode.com/problems/count-of-matches-in-tournament Easy
269 Math https://leetcode.com/problems/perfect-number Easy
270 Binary Search, Interactive https://leetcode.com/problems/guess-number-higher-or-lower Easy
271 Array https://leetcode.com/problems/distance-between-bus-stops Easy
272 Array https://leetcode.com/problems/binary-prefix-divisible-by-5 Easy
273 Array, String https://leetcode.com/problems/slowest-key Easy
274 Hash Table, String, Counting https://leetcode.com/problems/increasing-decreasing-string Easy
275 String https://leetcode.com/problems/length-of-last-word Easy
276 String, String Matching https://leetcode.com/problems/string-matching-in-an-array Easy
277 String https://leetcode.com/problems/maximum-score-after-splitting-a-string Easy
278 String, String Matching https://leetcode.com/problems/check-if-a-word-occurs-as-a-prefix-of-any-word-in-a-sentence
Easy
279 Array, Greedy https://leetcode.com/problems/minimum-operations-to-make-the-array-increasing Easy
280 Array, Hash Table, Counting https://leetcode.com/problems/number-of-equivalent-domino-pairs Easy
281 Array, Math, Geometry, Sorting, Matrix https://leetcode.com/problems/matrix-cells-in-distance-order Easy
282 Hash Table, String https://leetcode.com/problems/path-crossing Easy
283 Array, Matrix, Simulation https://leetcode.com/problems/shift-2d-grid Easy
284 String, Counting https://leetcode.com/problems/determine-if-string-halves-are-alike Easy
285 Array, Enumeration https://leetcode.com/problems/detect-pattern-of-length-m-repeated-k-or-more-times
Easy
286 Math https://leetcode.com/problems/base-7 Easy
287 Math, Bit Manipulation https://leetcode.com/problems/prime-number-of-set-bits-in-binary-representationEasy
288 Array, Counting https://leetcode.com/problems/maximum-population-year Easy
Hash Table, String, Bit Manipulation,
289 Sliding Window https://leetcode.com/problems/longest-nice-substring Easy
290 Array, Stack, Simulation https://leetcode.com/problems/build-an-array-with-stack-operations Easy
291 Array, Matrix, Simulation https://leetcode.com/problems/available-captures-for-rook Easy
292 Array, Matrix https://leetcode.com/problems/determine-whether-matrix-can-be-obtained-by-rotation
Easy
293 Array, Sorting https://leetcode.com/problems/average-salary-excluding-the-minimum-and-maximum-salary
Easy
294 String https://leetcode.com/problems/number-of-segments-in-a-string Easy
Hash Table, String, Sliding Window,
295 Counting https://leetcode.com/problems/substrings-of-size-three-with-distinct-characters Easy
296 Array, String, Stack https://leetcode.com/problems/crawler-log-folder Easy
297 Math, Bit Manipulation https://leetcode.com/problems/binary-gap Easy
298 Array https://leetcode.com/problems/check-if-array-is-sorted-and-rotated Easy
299 Two Pointers, String https://leetcode.com/problems/merge-strings-alternately Easy
300 Array, Math https://leetcode.com/problems/smallest-range-i Easy
301 Math https://leetcode.com/problems/calculate-money-in-leetcode-bank Easy
302 Array, Math, Geometry, Matrix https://leetcode.com/problems/surface-area-of-3d-shapes Easy
303 Array, Matrix https://leetcode.com/problems/special-positions-in-a-binary-matrix Easy
304 Array, String https://leetcode.com/problems/truncate-sentence Easy
305 Math https://leetcode.com/problems/construct-the-rectangle Easy
306 Array, Enumeration https://leetcode.com/problems/count-good-triplets Easy
307 Array, Math, Geometry, Matrix https://leetcode.com/problems/projection-area-of-3d-shapes Easy
308 Graph https://leetcode.com/problems/find-center-of-star-graph Easy
309 Array, Math https://leetcode.com/problems/sign-of-the-product-of-an-array Easy
310 Array https://leetcode.com/problems/defuse-the-bomb Easy
311 String https://leetcode.com/problems/minimum-changes-to-make-alternating-binary-string Easy
312 String https://leetcode.com/problems/reformat-the-string Easy
313 Array, Matrix https://leetcode.com/problems/image-smoother Easy
314 String https://leetcode.com/problems/replace-all-s-to-avoid-consecutive-repeating-characters
Easy
315 Array, String https://leetcode.com/problems/number-of-lines-to-write-string Easy
316 Array https://leetcode.com/problems/check-if-all-1s-are-at-least-length-k-places-away Easy
317 Array https://leetcode.com/problems/remove-one-element-to-make-the-array-strictly-increasing
Easy
318 Math, String https://leetcode.com/problems/determine-color-of-a-chessboard-square Easy
319 Hash Table, String https://leetcode.com/problems/largest-substring-between-two-equal-characters Easy
320 String, String Matching https://leetcode.com/problems/maximum-repeating-substring Easy
321 Array https://leetcode.com/problems/maximum-ascending-subarray-sum Easy
322 Array, String https://leetcode.com/problems/delete-columns-to-make-sorted Easy
323 Array https://leetcode.com/problems/count-number-of-pairs-with-absolute-difference-kEasy
324 Hash Table, Math, Counting https://leetcode.com/problems/maximum-number-of-balls-in-a-box Easy
325 Array https://leetcode.com/problems/three-consecutive-odds Easy
326 String https://leetcode.com/problems/replace-all-digits-with-characters Easy
327 Array, Greedy, Sorting https://leetcode.com/problems/minimum-subsequence-in-non-increasing-order Easy
328 Array, Sorting, Counting Sort https://leetcode.com/problems/height-checker Easy
329 Array, Math, Geometry https://leetcode.com/problems/largest-triangle-area Easy
330 Array, Sorting https://leetcode.com/problems/maximum-product-difference-between-two-pairs Easy
331 Hash Table, String, Counting https://leetcode.com/problems/check-if-one-string-swap-can-make-strings-equal Easy
332 String https://leetcode.com/problems/occurrences-after-bigram Easy
333 Array, Sorting, Heap (Priority Queue) https://leetcode.com/problems/relative-ranks Easy
334 String https://leetcode.com/problems/thousand-separator Easy
Array, Dynamic Programming,
335 Simulation https://leetcode.com/problems/get-maximum-in-generated-array Easy
336 Math, String, Greedy https://leetcode.com/problems/largest-odd-number-in-string Easy
337 Array https://leetcode.com/problems/number-of-rectangles-that-can-form-the-largest-square
Easy
338 String https://leetcode.com/problems/check-if-word-equals-summation-of-two-words Easy
339 Array, Hash Table, String https://leetcode.com/problems/shortest-completing-word Easy
340 Math https://leetcode.com/problems/count-odd-numbers-in-an-interval-range Easy
341 Array, String, Simulation https://leetcode.com/problems/final-value-of-variable-after-performing-operationsEasy
342 String https://leetcode.com/problems/generate-a-string-with-characters-that-have-odd-counts
Easy
343 Array, Binary Search, Sorting https://leetcode.com/problems/find-target-indices-after-sorting-array Easy
344 Hash Table, String https://leetcode.com/problems/number-of-different-integers-in-a-string Easy
Array, Two Pointers, Binary Search,
345 Sorting https://leetcode.com/problems/find-the-distance-value-between-two-arrays Easy
346 Array, Simulation https://leetcode.com/problems/teemo-attacking Easy
347 Array, Prefix Sum https://leetcode.com/problems/find-the-middle-index-in-array Easy
348 String, Greedy https://leetcode.com/problems/minimum-time-to-type-word-using-special-typewriterEasy
349 Hash Table, String https://leetcode.com/problems/count-vowel-substrings-of-a-string Easy
350 Array, Math https://leetcode.com/problems/find-greatest-common-divisor-of-array Easy
351 Math https://leetcode.com/problems/sum-of-digits-in-base-k Easy
352 Hash Table, Math https://leetcode.com/problems/count-largest-group Easy
353 String https://leetcode.com/problems/longer-contiguous-segments-of-ones-than-zeros Easy
354 Hash Table, String, Counting https://leetcode.com/problems/check-if-all-characters-have-equal-number-of-occurrences
Easy
355 Math https://leetcode.com/problems/convert-integer-to-the-sum-of-two-no-zero-integersEasy
356 Array, Sorting https://leetcode.com/problems/mean-of-array-after-removing-some-elements Easy
357 String https://leetcode.com/problems/rearrange-spaces-between-words Easy
358 String https://leetcode.com/problems/student-attendance-record-i Easy
359 Hash Table, String, Counting https://leetcode.com/problems/redistribute-characters-to-make-all-strings-equal Easy
360 Array, Greedy https://leetcode.com/problems/two-furthest-houses-with-different-colors Easy
361 Math https://leetcode.com/problems/prime-arrangements Easy
362 Array https://leetcode.com/problems/find-nearest-point-that-has-the-same-x-or-y-coordinate
Easy
363 Array https://leetcode.com/problems/maximum-difference-between-increasing-elements Easy
364 Math, String https://leetcode.com/problems/day-of-the-year Easy
Array, Hash Table, Sorting, Heap
365 (Priority Queue) https://leetcode.com/problems/find-subsequence-of-length-k-with-the-largest-sumEasy
366 Hash Table, String https://leetcode.com/problems/maximum-number-of-words-you-can-type Easy
367 Array, Hash Table, Prefix Sum https://leetcode.com/problems/check-if-all-the-integers-in-a-range-are-covered Easy
368 Array, Queue, Simulation https://leetcode.com/problems/time-needed-to-buy-tickets Easy
369 Math https://leetcode.com/problems/day-of-the-week Easy
370 Two Pointers, String https://leetcode.com/problems/reverse-prefix-of-word Easy
371 Math, Geometry https://leetcode.com/problems/valid-boomerang Easy
372 String https://leetcode.com/problems/reformat-date Easy
373 Hash Table, String https://leetcode.com/problems/second-largest-digit-in-a-string Easy
374 Array, Sorting https://leetcode.com/problems/minimum-difference-between-highest-and-lowest-of-k-scores
Easy
375 String https://leetcode.com/problems/number-of-strings-that-appear-as-substrings-in-word
Easy
376 Array, Hash Table https://leetcode.com/problems/two-out-of-three Easy
377 String, Greedy https://leetcode.com/problems/latest-time-by-replacing-hidden-digits Easy
378 String, Simulation https://leetcode.com/problems/sum-of-digits-of-string-after-convert Easy
379 String https://leetcode.com/problems/reformat-phone-number Easy
380 Array, Enumeration https://leetcode.com/problems/count-special-quadruplets Easy
381 Array, Simulation https://leetcode.com/problems/most-visited-sector-in-a-circular-track Easy
382 Math https://leetcode.com/problems/three-divisors Easy
383 Array, Hash Table, String, Counting https://leetcode.com/problems/kth-distinct-string-in-an-array Easy
Array, Hash Table, Design, Data
384 Stream https://leetcode.com/problems/design-an-ordered-stream Easy
385 String https://leetcode.com/problems/delete-characters-to-make-fancy-string Easy
386 Array, Matrix, Simulation https://leetcode.com/problems/convert-1d-array-into-2d-array Easy
387 Array, Sorting https://leetcode.com/problems/minimum-number-of-moves-to-seat-everyone Easy
388 Array, String https://leetcode.com/problems/check-if-string-is-a-prefix-of-array Easy
389 Hash Table, String https://leetcode.com/problems/rings-and-rods Easy
390 Math, String https://leetcode.com/problems/number-of-days-between-two-dates Easy
391 Array, Hash Table, String, Counting https://leetcode.com/problems/count-common-words-with-one-occurrence Easy
392 Two Pointers, String https://leetcode.com/problems/remove-palindromic-subsequences Easy
393 Array https://leetcode.com/problems/minimum-distance-to-the-target-element Easy
394 String https://leetcode.com/problems/check-if-numbers-are-ascending-in-a-sentence Easy
395 String, Greedy https://leetcode.com/problems/minimum-moves-to-convert-string Easy
396 Array, Two Pointers, String https://leetcode.com/problems/find-first-palindromic-string-in-the-array Easy
397 String https://leetcode.com/problems/check-if-binary-string-has-at-most-one-segment-of-ones
Easy
398 Math, Enumeration https://leetcode.com/problems/count-square-sum-triples Easy
Array, Hash Table, Sorting,
399 Enumeration https://leetcode.com/problems/finding-3-digit-even-numbers Easy
400 Array, String https://leetcode.com/problems/maximum-number-of-words-found-in-sentences Easy
401 Hash Table, String, Counting https://leetcode.com/problems/check-whether-two-strings-are-almost-equivalent Easy
402 Math https://leetcode.com/problems/a-number-after-a-double-reversal Easy
403 Array https://leetcode.com/problems/smallest-index-with-equal-value Easy
404 Math, String, Simulation https://leetcode.com/problems/fizz-buzz Easy
405 String https://leetcode.com/problems/number-of-valid-words-in-a-sentence Easy
406 https://leetcode.com/problems/check-if-all-as-appears-before-all-bs Easy
 Crack The Coding Interview - Dinesh Varyani
https://www.youtube.com/user/hubberspot?sub_confirmation=1

# Topic Question Difficulty

1 Hash Table, String, Sliding Window https://leetcode.com/problems/longest-substring-without-repeating-characters Medium

2 Linked List, Math, Recursion https://leetcode.com/problems/add-two-numbers Medium
3 Array, Two Pointers, Sorting https://leetcode.com/problems/3sum Medium
4 String, Dynamic Programming https://leetcode.com/problems/longest-palindromic-substring Medium
5 Array, Two Pointers, Greedy https://leetcode.com/problems/container-with-most-water Medium
6 Array, Binary Search https://leetcode.com/problems/search-in-rotated-sorted-array Medium
Array, Depth-First Search, Breadth-
7 First Search, Union Find, Matrix https://leetcode.com/problems/number-of-islands Medium
Hash Table, Linked List, Design,
8 Doubly-Linked List https://leetcode.com/problems/lru-cache Medium
9 Array, Sorting https://leetcode.com/problems/merge-intervals Medium
String, Dynamic Programming,
10 Backtracking https://leetcode.com/problems/generate-parentheses Medium
Array, Two Pointers, Binary Search,
11 Bit Manipulation https://leetcode.com/problems/find-the-duplicate-number Medium
12 Array, Prefix Sum https://leetcode.com/problems/product-of-array-except-self Medium
13 Array, Hash Table, Prefix Sum https://leetcode.com/problems/subarray-sum-equals-k Medium
14 Array, Dynamic Programming https://leetcode.com/problems/house-robber Medium
Array, Binary Search, Dynamic
15 Programming https://leetcode.com/problems/longest-increasing-subsequence Medium
16 Array, Dynamic Programming https://leetcode.com/problems/maximum-product-subarray Medium
Array, Dynamic Programming,
17 Breadth-First Search https://leetcode.com/problems/coin-change Medium
18 Array, Dynamic Programming, Greedy https://leetcode.com/problems/jump-game Medium
Hash Table, String, Dynamic
19 Programming, Trie, Memoization https://leetcode.com/problems/word-break Medium
20 Array, Binary Search https://leetcode.com/problems/find-first-and-last-position-of-element-in-sorted-array
Medium
21 Array, Backtracking https://leetcode.com/problems/permutations Medium
22 Array, Backtracking https://leetcode.com/problems/combination-sum Medium
23 Hash Table, String, Backtracking https://leetcode.com/problems/letter-combinations-of-a-phone-number Medium
Tree, Depth-First Search, Binary
24 Search Tree, Binary Tree https://leetcode.com/problems/validate-binary-search-tree Medium
25 Tree, Depth-First Search, Binary Tree https://leetcode.com/problems/lowest-common-ancestor-of-a-binary-tree Medium
26 Array, Two Pointers https://leetcode.com/problems/next-permutation Medium
27 Array, Two Pointers, Sorting https://leetcode.com/problems/sort-colors Medium
28 Linked List, Two Pointers https://leetcode.com/problems/remove-nth-node-from-end-of-list Medium
Depth-First Search, Breadth-First
29 Search, Graph, Topological Sort https://leetcode.com/problems/course-schedule Medium
30 Array, Backtracking, Matrix https://leetcode.com/problems/word-search Medium
31 Array, Backtracking, Bit Manipulation https://leetcode.com/problems/subsets Medium
32 Array, Hash Table, Union Find https://leetcode.com/problems/longest-consecutive-sequence Medium
Array, Divide and Conquer, Sorting,
33 Heap (Priority Queue), Quickselect https://leetcode.com/problems/kth-largest-element-in-an-array Medium
34 Hash Table, String, Sorting https://leetcode.com/problems/group-anagrams Medium
Math, Dynamic Programming,
35 Combinatorics https://leetcode.com/problems/unique-paths Medium
36 Array, Math, Matrix https://leetcode.com/problems/rotate-image Medium
Array, Hash Table, Divide and
37 Conquer, Tree, Binary Tree https://leetcode.com/problems/construct-binary-tree-from-preorder-and-inorder-traversal
Medium
38 Array, Math, Two Pointers https://leetcode.com/problems/rotate-array Medium
39 String, Stack, Recursion https://leetcode.com/problems/decode-string Medium
Array, Hash Table, Divide and
Conquer, Sorting, Heap (Priority
Queue), Bucket Sort, Counting,
40 Quickselect https://leetcode.com/problems/top-k-frequent-elements Medium
41 Hash Table, Linked List https://leetcode.com/problems/copy-list-with-random-pointer Medium
42 Tree, Depth-First Search, Binary Tree https://leetcode.com/problems/path-sum-iii Medium
Tree, Breadth-First Search, Binary
43 Tree https://leetcode.com/problems/binary-tree-level-order-traversal Medium
44 Array, Dynamic Programming, Greedy https://leetcode.com/problems/jump-game-ii Medium
45 Array, Dynamic Programming https://leetcode.com/problems/partition-equal-subset-sum Medium
Math, Dynamic Programming, Tree,
46 Binary Search Tree, Binary Tree https://leetcode.com/problems/unique-binary-search-trees Medium
47 Array, Dynamic Programming, Matrix https://leetcode.com/problems/maximal-square Medium
48 Array, Dynamic Programming, Greedy https://leetcode.com/problems/best-time-to-buy-and-sell-stock-ii Medium
49 Array, Dynamic Programming, Matrix https://leetcode.com/problems/minimum-path-sum Medium
 Array, Binary Search, Divide and
50 Conquer, Matrix https://leetcode.com/problems/search-a-2d-matrix-ii Medium
51 Math https://leetcode.com/problems/reverse-integer Medium
Linked List, Stack, Tree, Depth-First
52 Search, Binary Tree https://leetcode.com/problems/flatten-binary-tree-to-linked-list Medium
53 Hash Table, String, Design, Trie https://leetcode.com/problems/implement-trie-prefix-tree Medium
54 Array, Stack, Monotonic Stack https://leetcode.com/problems/daily-temperatures Medium
Hash Table, Two Pointers, String,
55 Greedy https://leetcode.com/problems/partition-labels Medium
Math, Dynamic Programming, Breadth-
56 First Search https://leetcode.com/problems/perfect-squares Medium
57 String, Dynamic Programming https://leetcode.com/problems/decode-ways Medium
Array, Hash Table, Greedy, Sorting,
58 Heap (Priority Queue), Counting https://leetcode.com/problems/task-scheduler Medium
59 Array, Matrix, Simulation https://leetcode.com/problems/spiral-matrix Medium
Array, Dynamic Programming,
60 Backtracking https://leetcode.com/problems/target-sum Medium
Depth-First Search, Breadth-First
61 Search, Graph, Topological Sort https://leetcode.com/problems/course-schedule-ii Medium
62 Hash Table, Linked List, Two Pointers https://leetcode.com/problems/linked-list-cycle-ii Medium
Dynamic Programming, Tree, Depth-
63 First Search, Binary Tree https://leetcode.com/problems/house-robber-iii Medium
Linked List, Two Pointers, Divide and
64 Conquer, Sorting, Merge Sort https://leetcode.com/problems/sort-list Medium
65 Hash Table, String, Sliding Window https://leetcode.com/problems/find-all-anagrams-in-a-string Medium
Tree, Depth-First Search, Breadth-First
66 Search, Binary Tree https://leetcode.com/problems/binary-tree-right-side-view Medium
67 String, Dynamic Programming https://leetcode.com/problems/palindromic-substrings Medium
68 Array, Breadth-First Search, Matrix https://leetcode.com/problems/rotting-oranges Medium
69 Array, Hash Table, Matrix https://leetcode.com/problems/set-matrix-zeroes Medium
70 Array, Binary Search, Matrix https://leetcode.com/problems/search-a-2d-matrix Medium
71 Array, Binary Search https://leetcode.com/problems/find-minimum-in-rotated-sorted-array Medium
Tree, Depth-First Search, Breadth-First
72 Search, Binary Tree https://leetcode.com/problems/populating-next-right-pointers-in-each-node Medium
Tree, Depth-First Search, Binary
73 Search Tree, Binary Tree https://leetcode.com/problems/kth-smallest-element-in-a-bst Medium
Array, Binary Search, Sliding Window,
74 Prefix Sum https://leetcode.com/problems/minimum-size-subarray-sum Medium
75 Array, Hash Table https://leetcode.com/problems/find-all-duplicates-in-an-array Medium
Tree, Depth-First Search, Breadth-First
76 Search, Binary Tree https://leetcode.com/problems/all-nodes-distance-k-in-binary-tree Medium
77 Linked List, Recursion https://leetcode.com/problems/swap-nodes-in-pairs Medium
78 Linked List https://leetcode.com/problems/reverse-linked-list-ii Medium
79 String, Dynamic Programming https://leetcode.com/problems/longest-common-subsequence Medium
Array, Binary Search, Sorting, Heap
80 (Priority Queue), Matrix https://leetcode.com/problems/kth-smallest-element-in-a-sorted-matrix Medium
81 Array, Two Pointers, Sorting https://leetcode.com/problems/4sum Medium
82 Array, Dynamic Programming https://leetcode.com/problems/best-time-to-buy-and-sell-stock-with-cooldown Medium
String, Dynamic Programming,
83 Backtracking https://leetcode.com/problems/palindrome-partitioning Medium
Linked List, Two Pointers, Stack,
84 Recursion https://leetcode.com/problems/reorder-list Medium
Array, Depth-First Search, Breadth-
85 First Search, Union Find, Matrix https://leetcode.com/problems/max-area-of-island Medium
86 Array, Two Pointers, Sorting https://leetcode.com/problems/3sum-closest Medium
Tree, Breadth-First Search, Binary
87 Tree https://leetcode.com/problems/binary-tree-zigzag-level-order-traversal Medium
88 Array, Binary Search https://leetcode.com/problems/find-peak-element Medium
Array, Hash Table, Math, Design,
89 Randomized https://leetcode.com/problems/insert-delete-getrandom-o1 Medium
Array, Math, Divide and Conquer,
Geometry, Sorting, Heap (Priority
90 Queue), Quickselect https://leetcode.com/problems/k-closest-points-to-origin Medium
91 Linked List https://leetcode.com/problems/odd-even-linked-list Medium
Depth-First Search, Breadth-First
92 Search, Graph, Topological Sort https://leetcode.com/problems/minimum-height-trees Medium
Array, Two Pointers, Stack, Greedy,
93 Sorting, Monotonic Stack https://leetcode.com/problems/shortest-unsorted-continuous-subarray Medium
Stack, Tree, Design, Binary Search
94 Tree, Binary Tree, Iterator https://leetcode.com/problems/binary-search-tree-iterator Medium
95 Array, Greedy, Sorting https://leetcode.com/problems/queue-reconstruction-by-height Medium
96 Tree, Binary Search Tree, Binary Tree https://leetcode.com/problems/delete-node-in-a-bst Medium
97 String, Dynamic Programming https://leetcode.com/problems/longest-palindromic-subsequence Medium
Array, Depth-First Search, Breadth-
First Search, Union Find, Graph,
98 Shortest Path https://leetcode.com/problems/evaluate-division Medium
 99 Array, Dynamic Programming https://leetcode.com/problems/house-robber-ii Medium
Hash Table, Depth-First Search,
100 Breadth-First Search, Graph https://leetcode.com/problems/clone-graph Medium
101 Array, Dynamic Programming https://leetcode.com/problems/coin-change-2 Medium
Depth-First Search, Breadth-First
102 Search, Union Find, Graph https://leetcode.com/problems/number-of-provinces Medium
103 Array, Binary Search https://leetcode.com/problems/single-element-in-a-sorted-array Medium
104 Array, Greedy https://leetcode.com/problems/gas-station Medium
Dynamic Programming, Backtracking,
105 Tree, Binary Search Tree, Binary Tree https://leetcode.com/problems/unique-binary-search-trees-ii Medium
Dynamic Programming, Depth-First
Search, Breadth-First Search, Graph,
106 Heap (Priority Queue), Shortest Path https://leetcode.com/problems/cheapest-flights-within-k-stops Medium
String, Stack, Greedy, Monotonic
107 Stack https://leetcode.com/problems/remove-k-digits Medium
Array, Depth-First Search, Breadth-
108 First Search, Union Find, Matrix https://leetcode.com/problems/surrounded-regions Medium
Binary Search, Tree, Depth-First
109 Search, Binary Tree https://leetcode.com/problems/count-complete-tree-nodes Medium
Array, Dynamic Programming,
Backtracking, Bit Manipulation,
110 Memoization, Bitmask https://leetcode.com/problems/partition-to-k-equal-sum-subsets Medium
111 String, Greedy, Sorting https://leetcode.com/problems/largest-number Medium
Array, Math, Enumeration, Number
112 Theory https://leetcode.com/problems/count-primes Medium
113 Array, Backtracking https://leetcode.com/problems/permutations-ii Medium
114 Array, Backtracking https://leetcode.com/problems/combination-sum-ii Medium
115 Array, Dynamic Programming https://leetcode.com/problems/triangle Medium
116 Linked List, Two Pointers https://leetcode.com/problems/remove-duplicates-from-sorted-list-ii Medium
117 Array, Hash Table, Matrix https://leetcode.com/problems/valid-sudoku Medium
Backtracking, Tree, Depth-First
118 Search, Binary Tree https://leetcode.com/problems/path-sum-ii Medium
Linked List, Divide and Conquer, Tree,
119 Binary Search Tree, Binary Tree https://leetcode.com/problems/convert-sorted-list-to-binary-search-tree Medium
120 Array https://leetcode.com/problems/insert-interval Medium
121 Array, Backtracking, Bit Manipulation https://leetcode.com/problems/subsets-ii Medium
122 Array, Dynamic Programming, Matrix https://leetcode.com/problems/unique-paths-ii Medium
Hash Table, String, Greedy, Sorting,
123 Heap (Priority Queue), Counting https://leetcode.com/problems/reorganize-string Medium
Hash Table, Two Pointers, String,
124 Sliding Window https://leetcode.com/problems/permutation-in-string Medium
125 Array, Hash Table, Sorting, Counting https://leetcode.com/problems/majority-element-ii Medium
Array, Hash Table, Divide and
126 Conquer, Tree, Binary Tree https://leetcode.com/problems/construct-binary-tree-from-inorder-and-postorder-traversal
Medium
127 Array, Dynamic Programming https://leetcode.com/problems/minimum-cost-for-tickets Medium
Hash Table, String, Trie, Sorting, Heap
(Priority Queue), Bucket Sort,
128 Counting https://leetcode.com/problems/top-k-frequent-words Medium
Array, Dynamic Programming,
129 Breadth-First Search, Matrix https://leetcode.com/problems/01-matrix Medium
130 Math, String, Simulation https://leetcode.com/problems/multiply-strings Medium
String, Depth-First Search, Design,
131 Trie https://leetcode.com/problems/design-add-and-search-words-data-structure Medium
132 Array, Stack, Monotonic Stack https://leetcode.com/problems/next-greater-element-ii Medium
133 Math, String, Stack https://leetcode.com/problems/basic-calculator-ii Medium
Array, String, Depth-First Search,
134 Breadth-First Search, Union Find https://leetcode.com/problems/accounts-merge Medium
135 Array, Two Pointers https://leetcode.com/problems/interval-list-intersections Medium
136 Linked List, Two Pointers https://leetcode.com/problems/rotate-list Medium
137 Tree, Depth-First Search, Binary Tree https://leetcode.com/problems/sum-root-to-leaf-numbers Medium
138 Math, Recursion https://leetcode.com/problems/powx-n Medium
Array, Binary Search, Sliding Window,
139 Prefix Sum https://leetcode.com/problems/max-consecutive-ones-iii Medium
String, Stack, Greedy, Monotonic
140 Stack https://leetcode.com/problems/remove-duplicate-letters Medium
Tree, Depth-First Search, Binary
141 Search Tree, Binary Tree https://leetcode.com/problems/recover-binary-search-tree Medium
Depth-First Search, Breadth-First
142 Search, Union Find, Graph https://leetcode.com/problems/is-graph-bipartite Medium
143 Array, Hash Table, Prefix Sum https://leetcode.com/problems/contiguous-array Medium
Array, Two Pointers, Binary Search,
144 Sorting, Heap (Priority Queue) https://leetcode.com/problems/find-k-closest-elements Medium
Hash Table, String, Sorting, Heap
(Priority Queue), Bucket Sort,
145 Counting https://leetcode.com/problems/sort-characters-by-frequency Medium
146 Hash Table, String, Sliding Window https://leetcode.com/problems/longest-repeating-character-replacement Medium
147 Array, Bit Manipulation https://leetcode.com/problems/single-number-ii Medium
Hash Table, Math, Dynamic
148 Programming, Heap (Priority Queue) https://leetcode.com/problems/ugly-number-ii Medium
149 Array, Bit Manipulation https://leetcode.com/problems/single-number-iii Medium
Depth-First Search, Breadth-First
Search, Graph, Heap (Priority Queue),
150 Shortest Path https://leetcode.com/problems/network-delay-time Medium
Hash Table, String, Divide and
151 Conquer, Sliding Window https://leetcode.com/problems/longest-substring-with-at-least-k-repeating-characters
Medium
152 Array, Dynamic Programming, Greedy https://leetcode.com/problems/best-time-to-buy-and-sell-stock-with-transaction-fee
Medium
153 Array https://leetcode.com/problems/non-decreasing-array Medium
154 String, Dynamic Programming https://leetcode.com/problems/interleaving-string Medium
155 Array, Matrix, Simulation https://leetcode.com/problems/game-of-life Medium
156 Array, Backtracking https://leetcode.com/problems/combinations Medium
Backtracking, Depth-First Search,
157 Breadth-First Search, Graph https://leetcode.com/problems/all-paths-from-source-to-target Medium
158 Array, Greedy https://leetcode.com/problems/increasing-triplet-subsequence Medium
Tree, Depth-First Search, Binary
159 Search Tree, Binary Tree https://leetcode.com/problems/trim-a-binary-search-tree Medium
Array, Binary Search, Dynamic
Programming, Sliding Window, Rolling
160 Hash, Hash Function https://leetcode.com/problems/maximum-length-of-repeated-subarray Medium
161 Array, Binary Search, Greedy https://leetcode.com/problems/capacity-to-ship-packages-within-d-days Medium
162 Array, Sliding Window https://leetcode.com/problems/subarray-product-less-than-k Medium
Linked List, Depth-First Search,
163 Doubly-Linked List https://leetcode.com/problems/flatten-a-multilevel-doubly-linked-list Medium
Tree, Depth-First Search, Breadth-First
164 Search, Binary Tree https://leetcode.com/problems/populating-next-right-pointers-in-each-node-ii Medium
Array, Divide and Conquer, Stack,
165 Tree, Monotonic Stack, Binary Tree https://leetcode.com/problems/maximum-binary-tree Medium
166 String, Stack https://leetcode.com/problems/minimum-remove-to-make-valid-parentheses Medium
167 Tree, Depth-First Search, Binary Tree https://leetcode.com/problems/distribute-coins-in-binary-tree Medium
Depth-First Search, Breadth-First
168 Search, Union Find, Graph https://leetcode.com/problems/redundant-connection Medium
Array, Dynamic Programming, Greedy,
169 Sorting https://leetcode.com/problems/non-overlapping-intervals Medium
170 String https://leetcode.com/problems/zigzag-conversion Medium
Tree, Depth-First Search, Breadth-First
171 Search, Binary Tree https://leetcode.com/problems/maximum-width-of-binary-tree Medium
Array, Stack, Tree, Binary Search Tree,
172 Monotonic Stack, Binary Tree https://leetcode.com/problems/construct-binary-search-tree-from-preorder-traversal
Medium
Math, String, Dynamic Programming,
173 Recursion, Memoization https://leetcode.com/problems/different-ways-to-add-parentheses Medium
174 Array, Binary Search https://leetcode.com/problems/search-in-rotated-sorted-array-ii Medium
175 Linked List, Math, Stack https://leetcode.com/problems/add-two-numbers-ii Medium
Tree, Depth-First Search, Binary
176 Search Tree, Binary Tree https://leetcode.com/problems/convert-bst-to-greater-tree Medium
177 Linked List, Two Pointers https://leetcode.com/problems/partition-list Medium
Array, Dynamic Programming, Binary
178 Indexed Tree, Segment Tree https://leetcode.com/problems/number-of-longest-increasing-subsequence Medium
String, Dynamic Programming, Stack,
179 Greedy https://leetcode.com/problems/valid-parenthesis-string Medium
180 Array, Dynamic Programming https://leetcode.com/problems/combination-sum-iv Medium
181 Array, Stack https://leetcode.com/problems/asteroid-collision Medium
Array, Math, Dynamic Programming,
182 Sorting https://leetcode.com/problems/largest-divisible-subset Medium
Array, Depth-First Search, Breadth-
183 First Search, Matrix https://leetcode.com/problems/pacific-atlantic-water-flow Medium
Array, Binary Search, Stack,
184 Monotonic Stack, Ordered Set https://leetcode.com/problems/132-pattern Medium
Array, Hash Table, Dynamic
185 Programming https://leetcode.com/problems/delete-and-earn Medium
Array, Dynamic Programming, Stack,
186 Monotonic Stack https://leetcode.com/problems/sum-of-subarray-minimums Medium
187 Array, Dynamic Programming, Matrix https://leetcode.com/problems/count-square-submatrices-with-all-ones Medium
Stack, Tree, Depth-First Search,
188 Design, Queue, Iterator https://leetcode.com/problems/flatten-nested-list-iterator Medium
189 String, Stack https://leetcode.com/problems/score-of-parentheses Medium
Array, Hash Table, Two Pointers,
190 String, Dynamic Programming https://leetcode.com/problems/longest-string-chain Medium
191 Tree, Depth-First Search, Binary Tree https://leetcode.com/problems/longest-univalue-path Medium
192 String, Backtracking, Bit Manipulation https://leetcode.com/problems/letter-case-permutation Medium
Tree, Breadth-First Search, Binary
193 Tree https://leetcode.com/problems/binary-tree-level-order-traversal-ii Medium
Tree, Depth-First Search, Breadth-First
194 Search, Binary Tree https://leetcode.com/problems/find-duplicate-subtrees Medium
 Dynamic Programming, Stack, Greedy,
195 Monotonic Stack https://leetcode.com/problems/minimum-cost-tree-from-leaf-values Medium
196 Array, Hash Table, Counting https://leetcode.com/problems/pairs-of-songs-with-total-durations-divisible-by-60Medium
Array, Hash Table, Bit Manipulation,
197 Trie https://leetcode.com/problems/maximum-xor-of-two-numbers-in-an-array Medium
198 Array, Heap (Priority Queue) https://leetcode.com/problems/find-k-pairs-with-smallest-sums Medium
199 Two Pointers, String https://leetcode.com/problems/reverse-words-in-a-string Medium
200 Array, Hash Table https://leetcode.com/problems/4sum-ii Medium
201 Hash Table, Math, String https://leetcode.com/problems/integer-to-roman Medium
Depth-First Search, Breadth-First
202 Search, Graph https://leetcode.com/problems/keys-and-rooms Medium
Array, Math, Dynamic Programming,
203 Recursion, Game Theory https://leetcode.com/problems/predict-the-winner Medium
Array, Divide and Conquer, Dynamic
Programming, Queue, Monotonic
204 Queue https://leetcode.com/problems/maximum-sum-circular-subarray Medium
205 Tree, Depth-First Search, Binary Tree https://leetcode.com/problems/delete-nodes-and-return-forest Medium
206 Array, Dynamic Programming https://leetcode.com/problems/arithmetic-slices Medium
207 Array, String, Dynamic Programming https://leetcode.com/problems/ones-and-zeroes Medium
Array, Design, Binary Indexed Tree,
208 Segment Tree https://leetcode.com/problems/range-sum-query-mutable Medium
209 Array, Two Pointers https://leetcode.com/problems/remove-duplicates-from-sorted-array-ii Medium
210 Hash Table, String, Trie, Sorting https://leetcode.com/problems/number-of-matching-subsequences Medium
211 Array, Binary Search https://leetcode.com/problems/koko-eating-bananas Medium
Array, Hash Table, String, Breadth-
212 First Search https://leetcode.com/problems/open-the-lock Medium
String, Tree, Depth-First Search,
Breadth-First Search, Design, Binary
213 Search Tree, Binary Tree https://leetcode.com/problems/serialize-and-deserialize-bst Medium
214 Array, Backtracking https://leetcode.com/problems/combination-sum-iii Medium
215 Array, Math, Stack https://leetcode.com/problems/evaluate-reverse-polish-notation Medium
216 Array, Sliding Window, Prefix Sum https://leetcode.com/problems/maximum-points-you-can-obtain-from-cards Medium
217 Math, Bit Manipulation https://leetcode.com/problems/divide-two-integers Medium
218 String, Dynamic Programming https://leetcode.com/problems/delete-operation-for-two-strings Medium
219 Array, Greedy, Sorting https://leetcode.com/problems/minimum-number-of-arrows-to-burst-balloons Medium
220 Array, Hash Table, Prefix Sum https://leetcode.com/problems/subarray-sums-divisible-by-k Medium
221 String, Backtracking https://leetcode.com/problems/restore-ip-addresses Medium
222 Array, Matrix, Simulation https://leetcode.com/problems/spiral-matrix-ii Medium
223 Math, Dynamic Programming https://leetcode.com/problems/integer-break Medium
224 Array, Dynamic Programming, Greedy https://leetcode.com/problems/wiggle-subsequence Medium
Array, Depth-First Search, Breadth-
225 First Search https://leetcode.com/problems/jump-game-iii Medium
226 Tree, Binary Search Tree, Binary Tree https://leetcode.com/problems/insert-into-a-binary-search-tree Medium
227 Array, Greedy, Sorting https://leetcode.com/problems/two-city-scheduling Medium
228 String, Stack https://leetcode.com/problems/remove-all-adjacent-duplicates-in-string-ii Medium
229 Array, Design, Matrix, Prefix Sum https://leetcode.com/problems/range-sum-query-2d-immutable Medium
230 Math, Dynamic Programming https://leetcode.com/problems/2-keys-keyboard Medium
231 Array, Stack, Simulation https://leetcode.com/problems/validate-stack-sequences Medium
Array, Two Pointers, Binary Search,
232 Greedy, Sorting https://leetcode.com/problems/valid-triangle-number Medium
Dynamic Programming, Tree,
233 Recursion, Memoization, Binary Tree https://leetcode.com/problems/all-possible-full-binary-trees Medium
234 Tree, Depth-First Search, Binary Tree https://leetcode.com/problems/binary-tree-pruning Medium
235 Math, Bit Manipulation https://leetcode.com/problems/sum-of-two-integers Medium
Stack, Design, Monotonic Stack, Data
236 Stream https://leetcode.com/problems/online-stock-span Medium
Tree, Depth-First Search, Binary
237 Search Tree, Binary Tree https://leetcode.com/problems/binary-search-tree-to-greater-sum-tree Medium
238 Math, Greedy https://leetcode.com/problems/maximum-swap Medium
239 Depth-First Search, Union Find, Graph https://leetcode.com/problems/most-stones-removed-with-same-row-or-column Medium
240 Tree, Depth-First Search, Binary Tree https://leetcode.com/problems/maximum-difference-between-node-and-ancestorMedium
Tree, Depth-First Search, Breadth-First
241 Search, Binary Tree https://leetcode.com/problems/deepest-leaves-sum Medium
Array, Depth-First Search, Breadth-
242 First Search, Matrix https://leetcode.com/problems/shortest-bridge Medium
243 Bit Manipulation https://leetcode.com/problems/bitwise-and-of-numbers-range Medium
Array, Sliding Window, Sorting, Bucket
244 Sort, Ordered Set https://leetcode.com/problems/contains-duplicate-iii Medium
245 Math, String, Simulation https://leetcode.com/problems/robot-bounded-in-circle Medium
246 String, Stack, Greedy https://leetcode.com/problems/minimum-add-to-make-parentheses-valid Medium
Array, Dynamic Programming, Greedy,
247 Sorting https://leetcode.com/problems/maximum-length-of-pair-chain Medium
 Depth-First Search, Breadth-First
248 Search, Union Find, Graph https://leetcode.com/problems/possible-bipartition Medium
Array, Hash Table, Greedy, Heap
249 (Priority Queue) https://leetcode.com/problems/split-array-into-consecutive-subsequences Medium
250 Array, Breadth-First Search, Matrix https://leetcode.com/problems/shortest-path-in-binary-matrix Medium
Tree, Depth-First Search, Breadth-First
251 Search, Binary Tree https://leetcode.com/problems/count-good-nodes-in-binary-tree Medium
Array, Linked List, Stack, Monotonic
252 Stack https://leetcode.com/problems/next-greater-node-in-linked-list Medium
Array, Divide and Conquer, Sorting,
253 Quickselect https://leetcode.com/problems/wiggle-sort-ii Medium
254 Array, Dynamic Programming https://leetcode.com/problems/partition-array-for-maximum-sum Medium
Array, Hash Table, Binary Search,
255 Dynamic Programming https://leetcode.com/problems/longest-arithmetic-subsequence Medium
256 Array, Dynamic Programming https://leetcode.com/problems/last-stone-weight-ii Medium
Tree, Depth-First Search, Breadth-First
257 Search, Binary Tree https://leetcode.com/problems/find-bottom-left-tree-value Medium
Depth-First Search, Breadth-First
258 Search, Union Find, Graph https://leetcode.com/problems/regions-cut-by-slashes Medium
Array, Dynamic Programming,
Backtracking, Bit Manipulation,
259 Bitmask https://leetcode.com/problems/beautiful-arrangement Medium
260 Array, Dynamic Programming, Matrix https://leetcode.com/problems/minimum-falling-path-sum Medium
261 Array, Matrix, Simulation https://leetcode.com/problems/diagonal-traverse Medium
Array, Queue, Sliding Window, Heap
(Priority Queue), Ordered Set,
262 Monotonic Queue https://leetcode.com/problems/longest-continuous-subarray-with-absolute-diff-less-than-or-equal-to-limit
Medium
263 Math, Two Pointers, String https://leetcode.com/problems/next-greater-element-iii Medium
Array, Binary Search, Depth-First
Search, Breadth-First Search, Union
264 Find, Heap (Priority Queue), Matrix https://leetcode.com/problems/path-with-minimum-effort Medium
265 Array, String, Trie https://leetcode.com/problems/search-suggestions-system Medium
Hash Table, String, Binary Search,
266 Design https://leetcode.com/problems/time-based-key-value-store Medium
267 Linked List, Sorting https://leetcode.com/problems/insertion-sort-list Medium
268 Two Pointers, String https://leetcode.com/problems/string-compression Medium
269 Math https://leetcode.com/problems/factorial-trailing-zeroes Medium
Array, Sorting, Heap (Priority Queue),
270 Simulation, Prefix Sum https://leetcode.com/problems/car-pooling Medium
Tree, Depth-First Search, Breadth-First
271 Search, Binary Tree https://leetcode.com/problems/find-largest-value-in-each-tree-row Medium
272 Dynamic Programming https://leetcode.com/problems/number-of-dice-rolls-with-target-sum Medium
Hash Table, Linked List, Design, Heap
273 (Priority Queue) https://leetcode.com/problems/design-twitter Medium
274 Array, Depth-First Search https://leetcode.com/problems/array-nesting Medium
Array, Math, Dynamic Programming,
275 Game Theory https://leetcode.com/problems/stone-game Medium
Hash Table, Tree, Depth-First Search,
276 Breadth-First Search, Binary Tree https://leetcode.com/problems/smallest-subtree-with-all-the-deepest-nodes Medium
277 Dynamic Programming https://leetcode.com/problems/knight-probability-in-chessboard Medium
278 Design, Segment Tree, Ordered Set https://leetcode.com/problems/my-calendar-i Medium
279 String, Dynamic Programming https://leetcode.com/problems/minimum-ascii-delete-sum-for-two-strings Medium
Tree, Breadth-First Search, Binary
280 Tree https://leetcode.com/problems/check-completeness-of-a-binary-tree Medium
281 Array https://leetcode.com/problems/maximize-distance-to-closest-person Medium
Math, Dynamic Programming, Bit
Manipulation, Memoization, Game
282 Theory, Bitmask https://leetcode.com/problems/can-i-win Medium
283 Hash Table, String, Sorting https://leetcode.com/problems/custom-sort-string Medium
284 Array, Hash Table https://leetcode.com/problems/brick-wall Medium
Depth-First Search, Breadth-First
285 Search, Graph, Topological Sort https://leetcode.com/problems/find-eventual-safe-states Medium
286 Array, Queue, Sorting, Simulation https://leetcode.com/problems/reveal-cards-in-increasing-order Medium
287 Array, Two Pointers, Greedy, Sorting https://leetcode.com/problems/boats-to-save-people Medium
Array, Hash Table, Divide and
288 Conquer, Tree, Binary Tree https://leetcode.com/problems/construct-binary-tree-from-preorder-and-postorder-traversal
Medium
Array, Dynamic Programming, Binary
289 Indexed Tree https://leetcode.com/problems/count-number-of-teams Medium
Hash Table, String, Bit Manipulation,
Sliding Window, Rolling Hash, Hash
290 Function https://leetcode.com/problems/repeated-dna-sequences Medium
291 Array, Hash Table, String https://leetcode.com/problems/find-and-replace-pattern Medium
Depth-First Search, Breadth-First
292 Search, Union Find, Graph https://leetcode.com/problems/number-of-operations-to-make-network-connected
Medium
Array, Divide and Conquer, Sorting,
Heap (Priority Queue), Merge Sort,
293 Bucket Sort, Radix Sort, Counting Sort https://leetcode.com/problems/sort-an-array Medium
294 Array, Backtracking, Matrix https://leetcode.com/problems/path-with-maximum-gold Medium
295 Linked List https://leetcode.com/problems/split-linked-list-in-parts Medium
Array, Two Pointers, Dynamic
296 Programming, Enumeration https://leetcode.com/problems/longest-mountain-in-array Medium
297 Array, String, Bit Manipulation https://leetcode.com/problems/maximum-product-of-word-lengths Medium
Array, Stack, Greedy, Sorting,
298 Monotonic Stack https://leetcode.com/problems/max-chunks-to-make-sorted Medium
299 String, Dynamic Programming https://leetcode.com/problems/flip-string-to-monotone-increasing Medium
Array, String, Backtracking, Bit
300 Manipulation https://leetcode.com/problems/maximum-length-of-a-concatenated-string-with-unique-characters
Medium
301 Tree, Breadth-First Search https://leetcode.com/problems/n-ary-tree-level-order-traversal Medium
Array, Hash Table, Two Pointers,
302 Binary Search, Sorting https://leetcode.com/problems/k-diff-pairs-in-an-array Medium
303 String, Stack, Tree, Binary Tree https://leetcode.com/problems/verify-preorder-serialization-of-a-binary-tree Medium
304 Dynamic Programming https://leetcode.com/problems/count-sorted-vowel-strings Medium
305 Array, Greedy https://leetcode.com/problems/minimum-domino-rotations-for-equal-row Medium
306 Array, Greedy, Matrix https://leetcode.com/problems/max-increase-to-keep-city-skyline Medium
Two Pointers, String, Dynamic
307 Programming https://leetcode.com/problems/push-dominoes Medium
308 Array, Greedy, Heap (Priority Queue) https://leetcode.com/problems/maximum-number-of-events-that-can-be-attendedMedium
309 Array, Dynamic Programming https://leetcode.com/problems/uncrossed-lines Medium
Tree, Depth-First Search, Breadth-First
310 Search, Binary Tree https://leetcode.com/problems/sum-of-nodes-with-even-valued-grandparent Medium
311 Array, Math, Bit Manipulation https://leetcode.com/problems/total-hamming-distance Medium
Array, Dynamic Programming, Sliding
312 Window https://leetcode.com/problems/maximum-sum-of-two-non-overlapping-subarraysMedium
313 String, Backtracking https://leetcode.com/problems/letter-tile-possibilities Medium
314 Array, Linked List, Design, Queue https://leetcode.com/problems/design-circular-queue Medium
315 Array, Two Pointers https://leetcode.com/problems/number-of-subarrays-with-bounded-maximum Medium
316 Array, Matrix, Prefix Sum https://leetcode.com/problems/matrix-block-sum Medium
317 Array, Dynamic Programming https://leetcode.com/problems/largest-sum-of-averages Medium
318 Tree, Depth-First Search, Binary Tree https://leetcode.com/problems/flip-equivalent-binary-trees Medium
Array, Dynamic Programming,
Backtracking, Bit Manipulation,
319 Bitmask https://leetcode.com/problems/matchsticks-to-square Medium
Divide and Conquer, Greedy, Tree,
Depth-First Search, Binary Search
320 Tree, Binary Tree https://leetcode.com/problems/balance-a-binary-search-tree Medium
321 Array, Stack https://leetcode.com/problems/exclusive-time-of-functions Medium
322 Hash Table, Math, String https://leetcode.com/problems/fraction-to-recurring-decimal Medium
Hash Table, Depth-First Search,
323 Breadth-First Search https://leetcode.com/problems/employee-importance Medium
324 Array, Sorting, Matrix https://leetcode.com/problems/sort-the-matrix-diagonally Medium
Array, Hash Table, Math, Sliding
325 Window https://leetcode.com/problems/count-number-of-nice-subarrays Medium
326 Math, Bit Manipulation, Recursion https://leetcode.com/problems/k-th-symbol-in-grammar Medium
327 Array, Greedy, Heap (Priority Queue) https://leetcode.com/problems/furthest-building-you-can-reach Medium
Array, Depth-First Search, Breadth-
328 First Search, Union Find, Matrix https://leetcode.com/problems/number-of-closed-islands Medium
329 Dynamic Programming https://leetcode.com/problems/out-of-boundary-paths Medium
Tree, Depth-First Search, Binary
330 Search Tree, Sorting, Binary Tree https://leetcode.com/problems/all-elements-in-two-binary-search-trees Medium
331 Array, Binary Search https://leetcode.com/problems/minimum-number-of-days-to-make-m-bouquets Medium
Array, Hash Table, Binary Search,
332 Sliding Window, Prefix Sum https://leetcode.com/problems/minimum-operations-to-reduce-x-to-zero Medium
Array, Dynamic Programming, Stack,
333 Matrix, Monotonic Stack https://leetcode.com/problems/count-submatrices-with-all-ones Medium
Math, Dynamic Programming, Game
334 Theory https://leetcode.com/problems/guess-number-higher-or-lower-ii Medium
Array, Dynamic Programming,
335 Breadth-First Search, Matrix https://leetcode.com/problems/as-far-from-land-as-possible Medium
Tree, Depth-First Search, Breadth-First
336 Search https://leetcode.com/problems/time-needed-to-inform-all-employees Medium
String, Stack, Greedy, Monotonic
337 Stack https://leetcode.com/problems/smallest-subsequence-of-distinct-characters Medium
338 Array, Hash Table, String, Trie https://leetcode.com/problems/replace-words Medium
Array, Hash Table, Backtracking, Bit
339 Manipulation https://leetcode.com/problems/increasing-subsequences Medium
Array, Hash Table, Binary Search,
340 Design https://leetcode.com/problems/snapshot-array Medium
341 Dynamic Programming https://leetcode.com/problems/domino-and-tromino-tiling Medium
Array, Hash Table, Dynamic
342 Programming https://leetcode.com/problems/length-of-longest-fibonacci-subsequence Medium
343 Linked List, Two Pointers https://leetcode.com/problems/swapping-nodes-in-a-linked-list Medium
344 Math, Backtracking, Bit Manipulation https://leetcode.com/problems/gray-code Medium
Array, Hash Table, Math, Geometry,
345 Sorting https://leetcode.com/problems/minimum-area-rectangle Medium
346 Array, Depth-First Search, Matrix https://leetcode.com/problems/battleships-in-a-board Medium
Hash Table, Tree, Depth-First Search,
347 Binary Tree https://leetcode.com/problems/most-frequent-subtree-sum Medium
Array, Hash Table, Math, Dynamic
348 Programming, Heap (Priority Queue) https://leetcode.com/problems/super-ugly-number Medium
349 String, String Matching https://leetcode.com/problems/repeated-string-match Medium
350 Array, String, Union Find, Graph https://leetcode.com/problems/satisfiability-of-equality-equations Medium
Hash Table, String, Depth-First Search,
351 Breadth-First Search, Union Find https://leetcode.com/problems/smallest-string-with-swaps Medium
352 Array, Math https://leetcode.com/problems/minimum-moves-to-equal-array-elements Medium
353 Dynamic Programming https://leetcode.com/problems/knight-dialer Medium
354 Hash Table, Linked List https://leetcode.com/problems/remove-zero-sum-consecutive-nodes-from-linked-list
Medium
355 Array, Dynamic Programming https://leetcode.com/problems/best-sightseeing-pair Medium
356 Array, Two Pointers, String, Sorting https://leetcode.com/problems/longest-word-in-dictionary-through-deleting Medium
357 Array, Hash Table, Math, Prefix Sum https://leetcode.com/problems/continuous-subarray-sum Medium
Array, Depth-First Search, Breadth-
358 First Search, Matrix https://leetcode.com/problems/minesweeper Medium
359 Hash Table, String, Counting https://leetcode.com/problems/bulls-and-cows Medium
360 Linked List, Design https://leetcode.com/problems/design-linked-list Medium
361 Array, Hash Table, Greedy, Sorting https://leetcode.com/problems/hand-of-straights Medium
362 Array, Math, Sorting https://leetcode.com/problems/minimum-moves-to-equal-array-elements-ii Medium
Tree, Breadth-First Search, Binary
363 Tree https://leetcode.com/problems/maximum-level-sum-of-a-binary-tree Medium
Hash Table, Tree, Depth-First Search,
364 Breadth-First Search, Binary Tree https://leetcode.com/problems/delete-leaves-with-a-given-value Medium
365 Array, Hash Table, String, Trie, Sorting https://leetcode.com/problems/longest-word-in-dictionary Medium
Array, Two Pointers, Binary Search,
366 Sorting https://leetcode.com/problems/heaters Medium
Linked List, Tree, Depth-First Search,
367 Breadth-First Search, Binary Tree https://leetcode.com/problems/linked-list-in-binary-tree Medium
Depth-First Search, Breadth-First
368 Search, Graph https://leetcode.com/problems/reorder-routes-to-make-all-paths-lead-to-the-city-zero
Medium
369 Math, Two Pointers, Binary Search https://leetcode.com/problems/sum-of-square-numbers Medium
370 Hash Table, String, Sliding Window https://leetcode.com/problems/number-of-substrings-containing-all-three-characters
Medium
371 Array, Greedy, Sorting https://leetcode.com/problems/advantage-shuffle Medium
Array, Hash Table, Math, Bit
372 Manipulation https://leetcode.com/problems/prison-cells-after-n-days Medium
Array, Dynamic Programming, Sliding
373 Window https://leetcode.com/problems/longest-turbulent-subarray Medium
Tree, Depth-First Search, Breadth-First
374 Search, Binary Tree https://leetcode.com/problems/add-one-row-to-tree Medium
375 Array, Binary Search https://leetcode.com/problems/find-the-smallest-divisor-given-a-threshold Medium
Array, Math, Dynamic Programming,
376 Game Theory https://leetcode.com/problems/stone-game-ii Medium
377 Array, Stack, Sorting, Monotonic Stack https://leetcode.com/problems/car-fleet Medium
Array, Hash Table, Sliding Window,
378 Prefix Sum https://leetcode.com/problems/binary-subarrays-with-sum Medium
379 String, Stack https://leetcode.com/problems/simplify-path Medium
380 Array, Dynamic Programming https://leetcode.com/problems/filling-bookcase-shelves Medium
String, Dynamic Programming, Bit
381 Manipulation https://leetcode.com/problems/number-of-good-ways-to-split-a-string Medium
382 Graph https://leetcode.com/problems/minimum-number-of-vertices-to-reach-all-nodes Medium
Array, Dynamic Programming, Queue,
Sliding Window, Heap (Priority Queue),
383 Monotonic Queue https://leetcode.com/problems/jump-game-vi Medium
384 Array, Dynamic Programming https://leetcode.com/problems/maximum-subarray-sum-with-one-deletion Medium
385 Tree, Depth-First Search, Binary Tree https://leetcode.com/problems/maximum-product-of-splitted-binary-tree Medium
Linked List, Math, Reservoir Sampling,
386 Randomized https://leetcode.com/problems/linked-list-random-node Medium
387 Hash Table, String, Design, Trie https://leetcode.com/problems/map-sum-pairs Medium
388 Array, Sorting, Counting Sort https://leetcode.com/problems/h-index Medium
389 String, Stack https://leetcode.com/problems/reverse-substrings-between-each-pair-of-parentheses
Medium
390 String, Stack https://leetcode.com/problems/decoded-string-at-index Medium
391 Array, String https://leetcode.com/problems/minimum-number-of-operations-to-move-all-balls-to-each-box
Medium
392 Array https://leetcode.com/problems/partition-array-into-disjoint-intervals Medium
Hash Table, String, Design, Hash
393 Function https://leetcode.com/problems/encode-and-decode-tinyurl Medium
394 Array, Stack, Greedy, Monotonic Stack https://leetcode.com/problems/find-the-most-competitive-subsequence Medium
395 String, Backtracking, Design, Iterator https://leetcode.com/problems/iterator-for-combination Medium
396 Array, Math https://leetcode.com/problems/global-and-local-inversions Medium
 Array, Hash Table, Greedy, Sorting,
397 Heap (Priority Queue) https://leetcode.com/problems/reduce-array-size-to-the-half Medium
398 Array, Dynamic Programming, Greedy https://leetcode.com/problems/video-stitching Medium
Array, Hash Table, Binary Search,
Dynamic Programming, Sliding
399 Window https://leetcode.com/problems/find-two-non-overlapping-sub-arrays-each-with-target-sum
Medium
400 String https://leetcode.com/problems/count-and-say Medium
401 Hash Table, String, Design https://leetcode.com/problems/design-underground-system Medium
402 Depth-First Search, Trie https://leetcode.com/problems/lexicographical-numbers Medium
403 Array, Dynamic Programming, Greedy https://leetcode.com/problems/greatest-sum-divisible-by-three Medium
404 Design, Segment Tree, Ordered Set https://leetcode.com/problems/my-calendar-ii Medium
405 Array, Dynamic Programming https://leetcode.com/problems/largest-plus-sign Medium
406 Math, Greedy https://leetcode.com/problems/broken-calculator Medium
407 Array, Binary Search, Sorting https://leetcode.com/problems/find-right-interval Medium
408 Two Pointers, String https://leetcode.com/problems/compare-version-numbers Medium
409 Array, Stack, Monotonic Stack https://leetcode.com/problems/maximum-width-ramp Medium
410 Array, Sliding Window https://leetcode.com/problems/grumpy-bookstore-owner Medium
Hash Table, Tree, Depth-First Search,
411 Breadth-First Search, Binary Tree https://leetcode.com/problems/lowest-common-ancestor-of-deepest-leaves Medium
412 Breadth-First Search, Graph https://leetcode.com/problems/shortest-path-with-alternating-colors Medium
413 Array, Two Pointers, Greedy, Sorting https://leetcode.com/problems/pancake-sorting Medium
414 Array, Dynamic Programming https://leetcode.com/problems/maximum-number-of-points-with-cost Medium
415 String, Dynamic Programming https://leetcode.com/problems/unique-substrings-in-wraparound-string Medium
416 String, Greedy, Sorting https://leetcode.com/problems/minimum-deletions-to-make-character-frequencies-unique
Medium
417 Hash Table, String https://leetcode.com/problems/minimum-number-of-steps-to-make-two-strings-anagram
Medium
Hash Table, String, Bit Manipulation,
418 Prefix Sum https://leetcode.com/problems/find-the-longest-substring-containing-vowels-in-even-counts
Medium
419 Array, Hash Table, Greedy, Sorting https://leetcode.com/problems/divide-array-in-sets-of-k-consecutive-numbers Medium
420 Array, Math, Greedy, Sorting https://leetcode.com/problems/smallest-range-ii Medium
421 Math, Binary Search https://leetcode.com/problems/reach-a-number Medium
Graph, Heap (Priority Queue), Shortest
422 Path https://leetcode.com/problems/path-with-maximum-probability Medium
423 Array, Hash Table, Greedy, Sorting https://leetcode.com/problems/array-of-doubled-pairs Medium
424 Dynamic Programming https://leetcode.com/problems/champagne-tower Medium
425 Array, Dynamic Programming, Greedy https://leetcode.com/problems/maximum-length-of-subarray-with-positive-product
Medium
Dynamic Programming, Graph,
426 Shortest Path https://leetcode.com/problems/find-the-city-with-the-smallest-number-of-neighbors-at-a-threshold-distance
Medium
427 Array, Greedy, Sorting https://leetcode.com/problems/maximum-area-of-a-piece-of-cake-after-horizontal-and-vertical-cuts
Medium
428 Array, Hash Table, String, Counting https://leetcode.com/problems/subdomain-visit-count Medium
Array, Linked List, Stack, Design,
429 Doubly-Linked List, Data Stream https://leetcode.com/problems/design-browser-history Medium
430 Array, Design, Iterator https://leetcode.com/problems/peeking-iterator Medium
431 Tree, Depth-First Search, Binary Tree https://leetcode.com/problems/number-of-good-leaf-nodes-pairs Medium
String, Tree, Depth-First Search,
432 Binary Tree https://leetcode.com/problems/smallest-string-starting-from-leaf Medium
433 String https://leetcode.com/problems/string-to-integer-atoi Medium
434 Hash Table, Math https://leetcode.com/problems/smallest-integer-divisible-by-k Medium
435 Array, Stack, Design https://leetcode.com/problems/design-a-stack-with-increment-operation Medium
436 Array, Greedy, Sorting, Counting https://leetcode.com/problems/minimum-increment-to-make-array-unique Medium
437 Hash Table, String, Design, Trie https://leetcode.com/problems/implement-magic-dictionary Medium
438 Array, Greedy, Sorting https://leetcode.com/problems/minimum-difference-between-largest-and-smallest-value-in-three-moves
Medium
439 Array, Greedy, Bit Manipulation, Matrix https://leetcode.com/problems/score-after-flipping-matrix Medium
Array, Dynamic Programming,
Backtracking, Bit Manipulation,
440 Memoization, Bitmask https://leetcode.com/problems/shopping-offers Medium
Array, Union Find, Minimum Spanning
441 Tree https://leetcode.com/problems/min-cost-to-connect-all-points Medium
442 Array, Binary Search, Sorting https://leetcode.com/problems/magnetic-force-between-two-balls Medium
443 String, Stack, Depth-First Search https://leetcode.com/problems/longest-absolute-file-path Medium
Array, Two Pointers, Binary Search,
444 Sorting https://leetcode.com/problems/number-of-subsequences-that-satisfy-the-given-sum-condition
Medium
445 Array, Dynamic Programming https://leetcode.com/problems/minimum-score-triangulation-of-polygon Medium
Dynamic Programming, Tree, Depth-
446 First Search, Binary Tree https://leetcode.com/problems/longest-zigzag-path-in-a-binary-tree Medium
447 Design, Ordered Set https://leetcode.com/problems/exam-room Medium
448 Array, Prefix Sum https://leetcode.com/problems/corporate-flight-bookings Medium
Array, Dynamic Programming, Bit
449 Manipulation https://leetcode.com/problems/bitwise-ors-of-subarrays Medium
Math, Dynamic Programming, Sliding
450 Window, Probability and Statistics https://leetcode.com/problems/new-21-game Medium
Array, Binary Search, Greedy, Sliding
451 Window, Sorting, Prefix Sum https://leetcode.com/problems/frequency-of-the-most-frequent-element Medium
452 Array, Hash Table, String https://leetcode.com/problems/word-subsets Medium
453 Math, Tree, Binary Tree https://leetcode.com/problems/path-in-zigzag-labelled-binary-tree Medium
Bit Manipulation, Tree, Depth-First
Search, Breadth-First Search, Binary
454 Tree https://leetcode.com/problems/pseudo-palindromic-paths-in-a-binary-tree Medium
455 Tree, Depth-First Search, Binary Tree https://leetcode.com/problems/binary-tree-coloring-game Medium
Array, Depth-First Search, Breadth-
456 First Search, Union Find, Matrix https://leetcode.com/problems/number-of-enclaves Medium
457 String, Greedy, Heap (Priority Queue) https://leetcode.com/problems/longest-happy-string Medium
458 Array, Hash Table https://leetcode.com/problems/group-the-people-given-the-group-size-they-belong-to
Medium
Array, Hash Table, Two Pointers,
459 Sorting, Counting https://leetcode.com/problems/3sum-with-multiplicity Medium
Array, Hash Table, Stack, Monotonic
460 Stack, Prefix Sum https://leetcode.com/problems/longest-well-performing-interval Medium
Array, Hash Table, Binary Search,
461 Greedy, Heap (Priority Queue) https://leetcode.com/problems/avoid-flood-in-the-city Medium
Hash Table, Math, Reservoir Sampling,
462 Randomized https://leetcode.com/problems/random-pick-index Medium
Array, Two Pointers, Binary Search,
463 Stack, Monotonic Stack https://leetcode.com/problems/shortest-subarray-to-be-removed-to-make-array-sorted
Medium
464 Array, Math, String, Sorting https://leetcode.com/problems/minimum-time-difference Medium
Math, Rejection Sampling,
465 Randomized, Probability and Statistics https://leetcode.com/problems/implement-rand10-using-rand7 Medium
Hash Table, Tree, Depth-First Search,
466 Breadth-First Search https://leetcode.com/problems/minimum-time-to-collect-all-apples-in-a-tree Medium
467 Math, Brainteaser https://leetcode.com/problems/bulb-switcher Medium
Array, String, Dynamic Programming,
468 Greedy https://leetcode.com/problems/minimum-time-to-make-rope-colorful Medium
Array, Hash Table, Dynamic
469 Programming https://leetcode.com/problems/longest-arithmetic-subsequence-of-given-difference
Medium
470 Array, Sorting https://leetcode.com/problems/remove-covered-intervals Medium
471 Math https://leetcode.com/problems/angle-between-hands-of-a-clock Medium
472 Backtracking, Breadth-First Search https://leetcode.com/problems/numbers-with-same-consecutive-differences Medium
473 Array, String https://leetcode.com/problems/shifting-letters Medium
Array, Hash Table, Dynamic
474 Programming https://leetcode.com/problems/binary-trees-with-factors Medium
Array, Hash Table, Math, Bit
475 Manipulation, Prefix Sum https://leetcode.com/problems/count-triplets-that-can-form-two-arrays-of-equal-xor
Medium
Math, Dynamic Programming,
476 Backtracking https://leetcode.com/problems/count-numbers-with-unique-digits Medium
477 Array, Bit Manipulation, Prefix Sum https://leetcode.com/problems/xor-queries-of-a-subarray Medium
478 Math, Greedy https://leetcode.com/problems/monotone-increasing-digits Medium
479 String, Backtracking https://leetcode.com/problems/split-array-into-fibonacci-sequence Medium
Array, Math, Design, Queue, Data
480 Stream https://leetcode.com/problems/product-of-the-last-k-numbers Medium
481 Array, Dynamic Programming https://leetcode.com/problems/k-concatenation-maximum-sum Medium
Array, Depth-First Search, Breadth-
First Search, Union Find, Matrix,
482 Counting https://leetcode.com/problems/count-servers-that-communicate Medium
483 Array, Hash Table, Prefix Sum https://leetcode.com/problems/make-sum-divisible-by-p Medium
484 Array, Hash Table, String https://leetcode.com/problems/find-duplicate-file-in-system Medium
485 Array, Math, Divide and Conquer https://leetcode.com/problems/beautiful-array Medium
Array, Math, Recursion, Queue,
486 Simulation https://leetcode.com/problems/find-the-winner-of-the-circular-game Medium
487 Array, Binary Search https://leetcode.com/problems/minimum-limit-of-balls-in-a-bag Medium
488 Math, String, Greedy https://leetcode.com/problems/minimum-swaps-to-make-strings-equal Medium
Array, Hash Table, Greedy, Sorting,
489 Heap (Priority Queue), Counting https://leetcode.com/problems/distant-barcodes Medium
490 Array, Greedy, Matrix https://leetcode.com/problems/find-valid-matrix-given-row-and-column-sums Medium
Depth-First Search, Breadth-First
491 Search, Graph https://leetcode.com/problems/flower-planting-with-no-adjacent Medium
492 Array, Sorting, Heap (Priority Queue) https://leetcode.com/problems/diagonal-traverse-ii Medium
Dynamic Programming, Memoization,
493 Sorting https://leetcode.com/problems/sort-integers-by-the-power-value Medium
494 Array, Hash Table, Counting https://leetcode.com/problems/check-if-array-pairs-are-divisible-by-k Medium
495 Math, Dynamic Programming https://leetcode.com/problems/rotate-function Medium
Hash Table, String, Breadth-First
496 Search https://leetcode.com/problems/minimum-genetic-mutation Medium
Array, Two Pointers, Binary Search,
497 Greedy, Sorting https://leetcode.com/problems/most-profit-assigning-work Medium
Dynamic Programming, Greedy, Bit
498 Manipulation, Memoization https://leetcode.com/problems/integer-replacement Medium
499 Array, Hash Table, Sliding Window https://leetcode.com/problems/maximum-erasure-value Medium
500 Linked List https://leetcode.com/problems/merge-in-between-linked-lists Medium
 Math, Dynamic Programming, Sliding
501 Window https://leetcode.com/problems/longest-subarray-of-1s-after-deleting-one-elementMedium
Array, Hash Table, Greedy, Sorting,
502 Counting https://leetcode.com/problems/least-number-of-unique-integers-after-k-removalsMedium
503 Math https://leetcode.com/problems/elimination-game Medium
Array, Binary Search, Matrix, Prefix
504 Sum https://leetcode.com/problems/maximum-side-length-of-a-square-with-sum-less-than-or-equal-to-threshold
Medium
505 Array, Dynamic Programming https://leetcode.com/problems/ways-to-make-a-fair-array Medium
506 Math, Geometry https://leetcode.com/problems/rectangle-area Medium
507 Math https://leetcode.com/problems/minimum-operations-to-make-array-equal Medium
508 Array, Dynamic Programming, Sorting https://leetcode.com/problems/best-team-with-no-conflicts Medium
509 Two Pointers, String https://leetcode.com/problems/swap-adjacent-in-lr-string Medium
Array, Hash Table, String, Sorting,
510 Counting https://leetcode.com/problems/rank-teams-by-votes Medium
511 String, Sliding Window https://leetcode.com/problems/replace-the-substring-for-balanced-string Medium
512 String, Backtracking https://leetcode.com/problems/additive-number Medium
Tree, Breadth-First Search, Design,
513 Binary Tree https://leetcode.com/problems/complete-binary-tree-inserter Medium
514 Enumeration https://leetcode.com/problems/sequential-digits Medium
515 Two Pointers, String, Prefix Sum https://leetcode.com/problems/jump-game-vii Medium
516 Array, Hash Table, String, Trie https://leetcode.com/problems/short-encoding-of-words Medium
517 String, Greedy https://leetcode.com/problems/break-a-palindrome Medium
518 Array, Sorting, Heap (Priority Queue) https://leetcode.com/problems/single-threaded-cpu Medium
519 Array, String, Sorting https://leetcode.com/problems/find-and-replace-in-string Medium
520 Array, Hash Table, Greedy, Prefix Sum https://leetcode.com/problems/maximum-number-of-non-overlapping-subarrays-with-sum-equals-target
Medium
521 Array, Binary Search, Sorting https://leetcode.com/problems/sum-of-mutated-array-closest-to-target Medium
522 String, Greedy https://leetcode.com/problems/partitioning-into-minimum-number-of-deci-binary-numbers
Medium
523 Tree, Depth-First Search, Binary Tree https://leetcode.com/problems/flip-binary-tree-to-match-preorder-traversal Medium
Tree, Depth-First Search, Breadth-First
Search, Union Find, Graph, Binary
524 Tree https://leetcode.com/problems/validate-binary-tree-nodes Medium
525 Array https://leetcode.com/problems/number-of-times-binary-string-is-prefix-aligned Medium
Array, Math, Dynamic Programming,
526 Prefix Sum https://leetcode.com/problems/number-of-sub-arrays-with-odd-sum Medium
527 String, Sliding Window https://leetcode.com/problems/swap-for-longest-repeated-character-substring Medium
528 Math, Binary Search, Number Theory https://leetcode.com/problems/ugly-number-iii Medium
529 Array, Binary Search https://leetcode.com/problems/h-index-ii Medium
Hash Table, String, Bit Manipulation,
530 Rolling Hash, Hash Function https://leetcode.com/problems/check-if-a-string-contains-all-binary-codes-of-size-k
Medium
Depth-First Search, Breadth-First
531 Search, Graph, Topological Sort https://leetcode.com/problems/course-schedule-iv Medium
Array, Stack, Monotonic Stack, Prefix
532 Sum https://leetcode.com/problems/maximum-subarray-min-product Medium
Tree, Depth-First Search, Breadth-First
533 Search, Binary Tree https://leetcode.com/problems/find-a-corresponding-node-of-a-binary-tree-in-a-clone-of-that-tree
Medium
Array, Two Pointers, Binary Search,
534 Prefix Sum https://leetcode.com/problems/ways-to-split-array-into-three-subarrays Medium
Math, Depth-First Search, Breadth-
535 First Search https://leetcode.com/problems/water-and-jug-problem Medium
536 Array, Simulation https://leetcode.com/problems/sum-of-even-numbers-after-queries Medium
537 Array, Math https://leetcode.com/problems/beautiful-arrangement-ii Medium
538 Hash Table, Linked List https://leetcode.com/problems/linked-list-components Medium
539 Array, Two Pointers, String https://leetcode.com/problems/expressive-words Medium
540 String https://leetcode.com/problems/validate-ip-address Medium
Array, Dynamic Programming, Depth-
541 First Search, Matrix, Simulation https://leetcode.com/problems/where-will-the-ball-fall Medium
542 Math, Geometry https://leetcode.com/problems/valid-square Medium
543 Array, Matrix, Simulation https://leetcode.com/problems/queens-that-can-attack-the-king Medium
Array, Hash Table, Binary Search,
544 Design https://leetcode.com/problems/online-election Medium
545 String, Sliding Window https://leetcode.com/problems/maximum-number-of-vowels-in-a-substring-of-given-length
Medium
546 Array, Two Pointers, Greedy, Sorting https://leetcode.com/problems/bag-of-tokens Medium
Array, Hash Table, Two Pointers,
547 Sorting https://leetcode.com/problems/max-number-of-k-sum-pairs Medium
548 Math, Binary Search https://leetcode.com/problems/nth-digit Medium
549 Greedy https://leetcode.com/problems/find-the-minimum-number-of-fibonacci-numbers-whose-sum-is-k
Medium
Dynamic Programming, Graph,
550 Topological Sort, Shortest Path https://leetcode.com/problems/number-of-ways-to-arrive-at-destination Medium
551 Array, Linked List, Design, Queue https://leetcode.com/problems/design-circular-deque Medium
Array, Math, Dynamic Programming,
552 Game Theory https://leetcode.com/problems/stone-game-vii Medium
553 Array, Hash Table, Sliding Window https://leetcode.com/problems/fruit-into-baskets Medium
554 Hash Table, String, Greedy, Counting https://leetcode.com/problems/construct-k-palindrome-strings Medium
555 String, Backtracking https://leetcode.com/problems/the-k-th-lexicographical-string-of-all-happy-strings-of-length-n
Medium
556 Hash Table, String https://leetcode.com/problems/alphabet-board-path Medium
Array, Dynamic Programming,
557 Breadth-First Search https://leetcode.com/problems/minimum-jumps-to-reach-home Medium
558 Hash Table, String, Sorting https://leetcode.com/problems/determine-if-two-strings-are-close Medium
559 Array, Hash Table, Math, Greedy https://leetcode.com/problems/rabbits-in-forest Medium
560 Array, Math, Randomized https://leetcode.com/problems/shuffle-an-array Medium
561 Array, Dynamic Programming https://leetcode.com/problems/maximum-absolute-sum-of-any-subarray Medium
562 String, Counting https://leetcode.com/problems/minimum-number-of-frogs-croaking Medium
Array, Math, Binary Search, Greedy,
563 Sorting, Heap (Priority Queue) https://leetcode.com/problems/sell-diminishing-valued-colored-balls Medium
564 Array, Math, Prefix Sum https://leetcode.com/problems/sum-of-absolute-differences-in-a-sorted-array Medium
565 String, Greedy https://leetcode.com/problems/minimum-suffix-flips Medium
Array, Depth-First Search, Breadth-
566 First Search, Union Find, Matrix https://leetcode.com/problems/count-sub-islands Medium
567 Array, Greedy, Sorting, Matrix https://leetcode.com/problems/largest-submatrix-with-rearrangements Medium
String, Binary Search, Sliding Window,
568 Prefix Sum https://leetcode.com/problems/get-equal-substrings-within-budget Medium
569 String, Dynamic Programming, Stack https://leetcode.com/problems/minimum-deletions-to-make-string-balanced Medium
570 Math https://leetcode.com/problems/the-kth-factor-of-n Medium
571 Math, Dynamic Programming https://leetcode.com/problems/rotated-digits Medium
572 String, Stack, Greedy https://leetcode.com/problems/minimum-insertions-to-balance-a-parentheses-string
Medium
573 Array, Hash Table, Math https://leetcode.com/problems/number-of-boomerangs Medium
574 Math, Sorting, Counting, Enumeration https://leetcode.com/problems/reordered-power-of-2 Medium
575 Graph https://leetcode.com/problems/maximal-network-rank Medium
576 Math, Dynamic Programming https://leetcode.com/problems/egg-drop-with-2-eggs-and-n-floors Medium
Hash Table, String, Bit Manipulation,
577 Prefix Sum https://leetcode.com/problems/number-of-wonderful-substrings Medium
Tree, Breadth-First Search, Binary
578 Tree https://leetcode.com/problems/even-odd-tree Medium
579 Array, String https://leetcode.com/problems/remove-comments Medium
580 Array, Hash Table https://leetcode.com/problems/restore-the-array-from-adjacent-pairs Medium
Array, Depth-First Search, Graph,
581 Topological Sort https://leetcode.com/problems/loud-and-rich Medium
582 Array, String, Trie https://leetcode.com/problems/remove-sub-folders-from-the-filesystem Medium
583 String, Greedy https://leetcode.com/problems/minimum-number-of-flips-to-make-the-binary-string-alternating
Medium
584 String, Greedy https://leetcode.com/problems/smallest-string-with-a-given-numeric-value Medium
Hash Table, String, Dynamic
585 Programming https://leetcode.com/problems/count-substrings-that-differ-by-one-character Medium
586 Hash Table, String, Sliding Window https://leetcode.com/problems/maximum-number-of-occurrences-of-a-substring Medium
587 String, Enumeration https://leetcode.com/problems/largest-time-for-given-digits Medium
588 Array, Dynamic Programming https://leetcode.com/problems/maximum-score-from-performing-multiplication-operations
Medium
Tree, Depth-First Search, Breadth-First
589 Search, Design, Binary Tree https://leetcode.com/problems/find-elements-in-a-contaminated-binary-tree Medium
Array, Math, Greedy, Sorting, Game
590 Theory https://leetcode.com/problems/maximum-number-of-coins-you-can-get Medium
591 Hash Table, Math, String https://leetcode.com/problems/reconstruct-original-digits-from-english Medium
592 Array, Dynamic Programming https://leetcode.com/problems/maximum-alternating-subsequence-sum Medium
593 String, Stack https://leetcode.com/problems/check-if-word-is-valid-after-substitutions Medium
594 Array, Depth-First Search, Union Find https://leetcode.com/problems/minimize-hamming-distance-after-swap-operations
Medium
Hash Table, String, Bit Manipulation,
595 Prefix Sum https://leetcode.com/problems/can-make-palindrome-from-substring Medium
Array, Depth-First Search, Breadth-
596 First Search, Union Find, Matrix https://leetcode.com/problems/check-if-there-is-a-valid-path-in-a-grid Medium
Array, Depth-First Search, Breadth-
597 First Search, Union Find, Matrix https://leetcode.com/problems/detect-cycles-in-2d-grid Medium
Dynamic Programming, Graph,
Topological Sort, Heap (Priority
598 Queue), Shortest Path https://leetcode.com/problems/number-of-restricted-paths-from-first-to-last-nodeMedium
Two Pointers, String, Trie, String
599 Matching https://leetcode.com/problems/camelcase-matching Medium
600 Array, Dynamic Programming, Greedy https://leetcode.com/problems/minimum-sideway-jumps Medium
Array, Two Pointers, Binary Search,
601 Sorting https://leetcode.com/problems/friends-of-appropriate-ages Medium
Array, Binary Search, Divide and
602 Conquer, Matrix https://leetcode.com/problems/find-a-peak-element-ii Medium
603 Two Pointers, String, Stack, Greedy https://leetcode.com/problems/minimum-number-of-swaps-to-make-the-string-balanced
Medium
Array, Two Pointers, Binary Search,
604 Sorting https://leetcode.com/problems/range-sum-of-sorted-subarray-sums Medium
605 Hash Table, String, Backtracking https://leetcode.com/problems/split-a-string-into-the-max-number-of-unique-substrings
Medium
606 Array, Heap (Priority Queue) https://leetcode.com/problems/process-tasks-using-servers Medium
607 Array, String, Binary Search https://leetcode.com/problems/maximum-number-of-removable-characters Medium
608 Array, Hash Table, Matrix https://leetcode.com/problems/flip-columns-for-maximum-number-of-equal-rowsMedium
609 Array, Design, Counting, Iterator https://leetcode.com/problems/rle-iterator Medium
610 Array, Two Pointers, Greedy, Sorting https://leetcode.com/problems/minimize-maximum-pair-sum-in-array Medium
611 Math, String, Simulation https://leetcode.com/problems/complex-number-multiplication Medium
612 Array, Dynamic Programming, Matrix https://leetcode.com/problems/maximum-non-negative-product-in-a-matrix Medium
Array, Stack, Greedy, Sorting,
613 Monotonic Stack https://leetcode.com/problems/the-number-of-weak-characters-in-the-game Medium
Array, Hash Table, String, Binary
614 Search, Sorting https://leetcode.com/problems/compare-strings-by-frequency-of-the-smallest-character
Medium
615 Array, Sorting https://leetcode.com/problems/arithmetic-subarrays Medium
616 Math, String https://leetcode.com/problems/number-of-substrings-with-only-1s Medium
617 Array, Sliding Window https://leetcode.com/problems/number-of-sub-arrays-of-size-k-and-average-greater-than-or-equal-to-threshold
Medium
618 Array, Two Pointers, Matrix https://leetcode.com/problems/rotating-the-box Medium
619 String, Greedy, Sorting https://leetcode.com/problems/check-if-a-string-can-break-another-string Medium
620 Array, Dynamic Programming, Matrix https://leetcode.com/problems/largest-1-bordered-square Medium
621 Array, Hash Table https://leetcode.com/problems/count-good-meals Medium
622 Math https://leetcode.com/problems/check-if-number-is-a-sum-of-powers-of-three Medium
623 Two Pointers, String, Greedy https://leetcode.com/problems/split-two-strings-to-make-palindrome Medium
Bit Manipulation, Depth-First Search,
624 Breadth-First Search https://leetcode.com/problems/pyramid-transition-matrix Medium
625 Array, Matrix, Simulation https://leetcode.com/problems/spiral-matrix-iii Medium
626 Array, Greedy, Sorting, Prefix Sum https://leetcode.com/problems/maximum-sum-obtained-of-any-permutation Medium
627 Array, Breadth-First Search, Matrix https://leetcode.com/problems/map-of-highest-peak Medium
628 String, Greedy https://leetcode.com/problems/string-without-aaa-or-bbb Medium
629 String, Sorting https://leetcode.com/problems/rearrange-words-in-a-sentence Medium
630 Array, Greedy, Heap (Priority Queue) https://leetcode.com/problems/maximum-number-of-eaten-apples Medium
631 Array, Greedy, Heap (Priority Queue) https://leetcode.com/problems/maximum-average-pass-ratio Medium
632 Array, String, Greedy https://leetcode.com/problems/delete-columns-to-make-sorted-ii Medium
633 Array, Bit Manipulation https://leetcode.com/problems/decode-xored-permutation Medium
Array, Divide and Conquer, Tree,
634 Matrix https://leetcode.com/problems/construct-quad-tree Medium
635 Array, Simulation https://leetcode.com/problems/find-the-winner-of-an-array-game Medium
636 Array, Hash Table, Greedy, Counting https://leetcode.com/problems/equal-sum-arrays-with-minimum-number-of-operations
Medium
637 Binary Search, Greedy https://leetcode.com/problems/maximum-value-at-a-given-index-in-a-bounded-array
Medium
638 Array, Breadth-First Search, Matrix https://leetcode.com/problems/snakes-and-ladders Medium
639 String, Bit Manipulation https://leetcode.com/problems/number-of-steps-to-reduce-a-number-in-binary-representation-to-one
Medium
640 Array, Math https://leetcode.com/problems/maximum-of-absolute-value-expression Medium
641 Math, Divide and Conquer https://leetcode.com/problems/super-pow Medium
642 Array, Binary Search, Simulation https://leetcode.com/problems/find-latest-group-of-size-m Medium
643 String https://leetcode.com/problems/remove-all-occurrences-of-a-substring Medium
Array, Dynamic Programming,
Backtracking, Bit Manipulation,
644 Bitmask https://leetcode.com/problems/minimum-number-of-work-sessions-to-finish-the-tasks
Medium
645 Array, Greedy https://leetcode.com/problems/maximum-number-of-consecutive-values-you-can-make
Medium
Array, Math, Greedy, Sorting, Heap
646 (Priority Queue), Game Theory https://leetcode.com/problems/stone-game-vi Medium
Array, Two Pointers, Binary Search,
647 Greedy https://leetcode.com/problems/maximum-distance-between-a-pair-of-values Medium
648 Array, Hash Table, String https://leetcode.com/problems/groups-of-special-equivalent-strings Medium
649 Math, Greedy, Heap (Priority Queue) https://leetcode.com/problems/maximum-score-from-removing-stones Medium
Array, Binary Search, Sorting, Ordered
650 Set https://leetcode.com/problems/minimum-absolute-sum-difference Medium
651 Array, Math, Geometry https://leetcode.com/problems/queries-on-number-of-points-inside-a-circle Medium
652 String, Greedy, Queue https://leetcode.com/problems/dota2-senate Medium
Array, Binary Search, Dynamic
653 Programming, Sorting https://leetcode.com/problems/maximum-earnings-from-taxi Medium
Array, Hash Table, Greedy, Bit
654 Manipulation https://leetcode.com/problems/cinema-seat-allocation Medium
655 String, Recursion https://leetcode.com/problems/find-kth-bit-in-nth-binary-string Medium
656 Array, Hash Table, Prefix Sum https://leetcode.com/problems/minimum-moves-to-make-array-complementary Medium
657 Math, String https://leetcode.com/problems/number-of-ways-to-split-a-string Medium
658 Array, String, Simulation https://leetcode.com/problems/print-words-vertically Medium
659 Bit Manipulation https://leetcode.com/problems/minimum-flips-to-make-a-or-b-equal-to-c Medium
660 Array, Dynamic Programming, Matrix https://leetcode.com/problems/minimize-the-difference-between-target-and-chosen-elements
Medium
661 Array, Binary Search https://leetcode.com/problems/minimum-speed-to-arrive-on-time Medium
662 Hash Table, String, Prefix Sum https://leetcode.com/problems/unique-length-3-palindromic-subsequences Medium
Math, Binary Search, Reservoir
Sampling, Prefix Sum, Ordered Set,
663 Randomized https://leetcode.com/problems/random-point-in-non-overlapping-rectangles Medium
664 Array, Greedy https://leetcode.com/problems/minimum-numbers-of-function-calls-to-make-target-array
Medium
665 Array, Greedy, Matrix https://leetcode.com/problems/minimum-swaps-to-arrange-a-binary-grid Medium
666 Array, String, Backtracking https://leetcode.com/problems/find-unique-binary-string Medium
667 Array, String https://leetcode.com/problems/valid-tic-tac-toe-state Medium
668 Array, Two Pointers, Sorting https://leetcode.com/problems/the-k-strongest-values-in-an-array Medium
Array, Linked List, Design, Queue,
669 Data Stream https://leetcode.com/problems/design-front-middle-back-queue Medium
Array, Dynamic Programming,
Backtracking, Bit Manipulation,
670 Bitmask https://leetcode.com/problems/maximum-compatibility-score-sum Medium
671 Array, Matrix, Prefix Sum https://leetcode.com/problems/grid-game Medium
672 Tree, Depth-First Search, Binary Tree https://leetcode.com/problems/insufficient-nodes-in-root-to-leaf-paths Medium
673 Array, Hash Table https://leetcode.com/problems/tuple-with-same-product Medium
674 Math, Geometry https://leetcode.com/problems/mirror-reflection Medium
675 Array, Hash Table, Greedy, Sorting https://leetcode.com/problems/find-original-array-from-doubled-array Medium
Array, Hash Table, Two Pointers,
676 String, Sorting https://leetcode.com/problems/longest-uncommon-subsequence-ii Medium
677 Array, Hash Table, Math, Counting https://leetcode.com/problems/count-nice-pairs-in-an-array Medium
678 String, Stack, Depth-First Search https://leetcode.com/problems/mini-parser Medium
679 Math, String, Simulation https://leetcode.com/problems/solve-the-equation Medium
String, Tree, Depth-First Search,
680 Binary Tree https://leetcode.com/problems/step-by-step-directions-from-a-binary-tree-node-to-another
Medium
681 Array, Bit Manipulation https://leetcode.com/problems/utf-8-validation Medium
Tree, Depth-First Search, Breadth-First
682 Search https://leetcode.com/problems/number-of-nodes-in-the-sub-tree-with-the-same-label
Medium
683 Array, Backtracking https://leetcode.com/problems/construct-the-lexicographically-largest-valid-sequence
Medium
Math, Geometry, Rejection Sampling,
684 Randomized https://leetcode.com/problems/generate-random-point-in-a-circle Medium
685 Two Pointers, String, Greedy https://leetcode.com/problems/minimum-adjacent-swaps-to-reach-the-kth-smallest-number
Medium
686 String, Stack, Greedy https://leetcode.com/problems/maximum-score-from-removing-substrings Medium
Array, Dynamic Programming,
687 Backtracking https://leetcode.com/problems/closest-dessert-cost Medium
688 String, Sliding Window https://leetcode.com/problems/longest-substring-of-all-vowels-in-order Medium
689 Math, String https://leetcode.com/problems/count-number-of-homogenous-substrings Medium
Array, Depth-First Search, Breadth-
690 First Search, Matrix https://leetcode.com/problems/coloring-a-border Medium
Array, Heap (Priority Queue), Ordered
691 Set https://leetcode.com/problems/the-number-of-the-smallest-unoccupied-chair Medium
692 Array, Hash Table, String https://leetcode.com/problems/vowel-spellchecker Medium
693 Array, Dynamic Programming https://leetcode.com/problems/minimum-total-space-wasted-with-k-resizing-operations
Medium
694 Linked List, Two Pointers https://leetcode.com/problems/delete-the-middle-node-of-a-linked-list Medium
Math, Dynamic Programming,
695 Brainteaser, Probability and Statistics https://leetcode.com/problems/airplane-seat-assignment-probability Medium
696 Array, Hash Table, Prefix Sum https://leetcode.com/problems/intervals-between-identical-elements Medium
697 Array, Hash Table https://leetcode.com/problems/minimum-absolute-difference-queries Medium
698 Tree, Binary Tree https://leetcode.com/problems/maximum-binary-tree-ii Medium
String, Dynamic Programming,
Backtracking, Bit Manipulation,
699 Bitmask https://leetcode.com/problems/maximum-product-of-the-length-of-two-palindromic-subsequences
Medium
700 Array, Design, Matrix https://leetcode.com/problems/subrectangle-queries Medium
Math, Two Pointers, Binary Search,
701 Interactive https://leetcode.com/problems/find-positive-integer-solution-for-a-given-equationMedium
702 Math, Bit Manipulation, Simulation https://leetcode.com/problems/concatenation-of-consecutive-binary-numbers Medium
703 Math https://leetcode.com/problems/convert-to-base-2 Medium
704 Array, Hash Table https://leetcode.com/problems/finding-the-users-active-minutes Medium
705 Array, Bit Manipulation, Prefix Sum https://leetcode.com/problems/maximum-xor-for-each-query Medium
706 Array, Greedy https://leetcode.com/problems/maximum-number-of-weeks-for-which-you-can-work Medium
707 Array, Breadth-First Search, Matrix https://leetcode.com/problems/nearest-exit-from-entrance-in-maze Medium
708 Array, Brainteaser, Simulation https://leetcode.com/problems/last-moment-before-all-ants-fall-out-of-a-plank Medium
709 Array, Binary Indexed Tree, Simulation https://leetcode.com/problems/queries-on-a-permutation-with-key Medium
710 Math https://leetcode.com/problems/prime-palindrome Medium
711 Array, Hash Table, String https://leetcode.com/problems/making-file-names-unique Medium
712 Two Pointers, String, Greedy https://leetcode.com/problems/largest-merge-of-two-strings Medium
String, Binary Search, Sliding Window,
713 Prefix Sum https://leetcode.com/problems/maximize-the-confusion-of-an-exam Medium
714 Array, Greedy, Matrix https://leetcode.com/problems/reconstruct-a-2-row-binary-matrix Medium
715 Array, Simulation https://leetcode.com/problems/average-waiting-time Medium
716 Array, Stack, Monotonic Stack https://leetcode.com/problems/sum-of-subarray-ranges Medium
Array, Binary Search, Dynamic
Programming, Sorting, Heap (Priority
717 Queue) https://leetcode.com/problems/two-best-non-overlapping-events Medium
718 Array, Breadth-First Search https://leetcode.com/problems/minimum-operations-to-convert-number Medium
719 Array, Dynamic Programming https://leetcode.com/problems/first-day-where-you-have-been-in-all-the-rooms Medium
 Math, Binary Search, Prefix Sum,
720 Randomized https://leetcode.com/problems/random-pick-with-weight Medium
721 Math, String, Simulation https://leetcode.com/problems/fraction-addition-and-subtraction Medium
722 Math, Dynamic Programming https://leetcode.com/problems/number-of-sets-of-k-non-overlapping-line-segments
Medium
Array, String, Divide and Conquer,
Sorting, Heap (Priority Queue),
723 Quickselect https://leetcode.com/problems/find-the-kth-largest-integer-in-the-array Medium
724 Array, Hash Table, Two Pointers https://leetcode.com/problems/circular-array-loop Medium
725 Array, Greedy, Sorting https://leetcode.com/problems/maximum-ice-cream-bars Medium
726 Array, Sorting https://leetcode.com/problems/reduction-operations-to-make-the-array-elements-equal
Medium
727 Array, Math, Two Pointers, Sorting https://leetcode.com/problems/moving-stones-until-consecutive-ii Medium
728 String, Greedy https://leetcode.com/problems/maximum-binary-string-after-change Medium
729 Array, Math, Geometry https://leetcode.com/problems/minimum-area-rectangle-ii Medium
Hash Table, Math, Reservoir Sampling,
730 Randomized https://leetcode.com/problems/random-flip-matrix Medium
731 Array, Greedy, Sorting https://leetcode.com/problems/eliminate-maximum-number-of-monsters Medium
732 Math, Greedy, Game Theory https://leetcode.com/problems/sum-game Medium
Array, Hash Table, Binary Search,
733 Design, Segment Tree https://leetcode.com/problems/range-frequency-queries Medium
734 Hash Table, String, Counting https://leetcode.com/problems/sum-of-beauty-of-all-substrings Medium
Array, Tree, Depth-First Search, Binary
735 Tree https://leetcode.com/problems/count-nodes-with-the-highest-score Medium
736 String, Backtracking https://leetcode.com/problems/splitting-a-string-into-descending-consecutive-values
Medium
Array, Hash Table, Greedy, Sorting,
737 Counting https://leetcode.com/problems/largest-values-from-labels Medium
738 Hash Table, String https://leetcode.com/problems/can-convert-string-in-k-moves Medium
Array, Hash Table, String, Graph,
739 Topological Sort https://leetcode.com/problems/find-all-possible-recipes-from-given-supplies Medium
740 Array, Binary Search https://leetcode.com/problems/minimized-maximum-of-products-distributed-to-any-store
Medium
741 String, Stack https://leetcode.com/problems/maximum-nesting-depth-of-two-valid-parentheses-strings
Medium
Array, String, Binary Search, Prefix
742 Sum https://leetcode.com/problems/plates-between-candles Medium
Array, Divide and Conquer, Bit
Manipulation, Heap (Priority Queue),
743 Matrix, Prefix Sum, Quickselect https://leetcode.com/problems/find-kth-largest-xor-coordinate-value Medium
744 Math, Recursion https://leetcode.com/problems/count-good-numbers Medium
745 Array, Hash Table, String, Sorting https://leetcode.com/problems/invalid-transactions Medium
746 Array, Hash Table, String https://leetcode.com/problems/evaluate-the-bracket-pairs-of-a-string Medium
Array, Depth-First Search, Breadth-
747 First Search, Matrix https://leetcode.com/problems/find-all-groups-of-farmland Medium
748 Array, Greedy https://leetcode.com/problems/decrease-elements-to-make-array-zigzag Medium
749 Array, Hash Table, Design https://leetcode.com/problems/finding-pairs-with-a-certain-sum Medium
750 String, Greedy https://leetcode.com/problems/minimum-number-of-swaps-to-make-the-binary-string-alternating
Medium
751 Array, Greedy https://leetcode.com/problems/merge-triplets-to-form-target-triplet Medium
Math, String, Dynamic Programming,
752 Combinatorics https://leetcode.com/problems/vowels-of-all-substrings Medium
753 String, Backtracking https://leetcode.com/problems/ambiguous-coordinates Medium
754 Array, Prefix Sum https://leetcode.com/problems/describe-the-painting Medium
755 Array, Math, Dynamic Programming https://leetcode.com/problems/optimal-division Medium
Hash Table, Design, Heap (Priority
756 Queue), Data Stream, Ordered Set https://leetcode.com/problems/stock-price-fluctuation Medium
Math, Dynamic Programming,
757 Probability and Statistics https://leetcode.com/problems/soup-servings Medium
758 Two Pointers, String https://leetcode.com/problems/minimum-length-of-string-after-deleting-similar-ends
Medium
759 Array, Heap (Priority Queue) https://leetcode.com/problems/remove-stones-to-minimize-the-total Medium
760 Array, Math, Sorting, Matrix https://leetcode.com/problems/minimum-operations-to-make-a-uni-value-grid Medium
761 Array, Greedy, Matrix https://leetcode.com/problems/maximum-matrix-sum Medium
762 Array https://leetcode.com/problems/sum-of-beauty-in-the-array Medium
763 Array, Math, Matrix https://leetcode.com/problems/magic-squares-in-grid Medium
764 Array, Binary Search, Sorting https://leetcode.com/problems/most-beautiful-item-for-each-query Medium
765 Design, Heap (Priority Queue) https://leetcode.com/problems/seat-reservation-manager Medium
766 String https://leetcode.com/problems/binary-string-with-substrings-representing-1-to-n Medium
767 Array https://leetcode.com/problems/watering-plants Medium
768 Array, Math, Dynamic Programming https://leetcode.com/problems/number-of-smooth-descent-periods-of-a-stock Medium
769 Array, Hash Table, String https://leetcode.com/problems/people-whose-list-of-favorite-companies-is-not-a-subset-of-another-list
Medium
770 String, Dynamic Programming, Greedy https://leetcode.com/problems/minimum-number-of-buckets-required-to-collect-rainwater-from-houses
Medium
771 Hash Table, Math https://leetcode.com/problems/powerful-integers Medium
772 Math, Backtracking, Bit Manipulation https://leetcode.com/problems/circular-permutation-in-binary-representation Medium
773 Array, Hash Table, Math, Two Pointers https://leetcode.com/problems/number-of-ways-where-square-of-number-is-equal-to-product-of-two-numbers
Medium
774 Math, Geometry https://leetcode.com/problems/circle-and-rectangle-overlapping Medium
775 Array, Greedy, Sorting https://leetcode.com/problems/array-with-elements-not-equal-to-average-of-neighbors
Medium
776 String, Stack, Greedy https://leetcode.com/problems/check-if-a-parentheses-string-can-be-valid Medium
777 Math https://leetcode.com/problems/simplified-fractions Medium
778 String, Breadth-First Search https://leetcode.com/problems/lexicographically-smallest-string-after-applying-operations
Medium
Hash Table, String, Counting, Prefix
779 Sum https://leetcode.com/problems/change-minimum-characters-to-satisfy-one-of-three-conditions
Medium
780 String, Greedy https://leetcode.com/problems/maximum-value-after-insertion Medium
781 Array, Math https://leetcode.com/problems/adding-two-negabinary-numbers Medium
782 Math https://leetcode.com/problems/number-of-burgers-with-no-waste-of-ingredients Medium
783 Array, Greedy https://leetcode.com/problems/removing-minimum-and-maximum-from-array Medium
Array, Dynamic Programming, Prefix
784 Sum https://leetcode.com/problems/find-good-days-to-rob-the-bank Medium
Array, Hash Table, Breadth-First
785 Search, Sorting https://leetcode.com/problems/get-watched-videos-by-your-friends Medium
786 Array, Sorting https://leetcode.com/problems/filter-restaurants-by-vegan-friendly-price-and-distance
Medium
Array, Math, Depth-First Search,
Breadth-First Search, Graph,
787 Geometry https://leetcode.com/problems/detonate-the-maximum-bombs Medium
788 Array, Two Pointers, String https://leetcode.com/problems/sentence-similarity-iii Medium
789 Array, Breadth-First Search, Graph https://leetcode.com/problems/the-time-when-the-network-becomes-idle Medium
790 Array, Greedy, Matrix https://leetcode.com/problems/minimum-cost-homecoming-of-a-robot-in-a-grid Medium
Array, Binary Search, Simulation,
791 Prefix Sum https://leetcode.com/problems/find-the-student-that-will-replace-the-chalk Medium
792 Array, Math, Simulation https://leetcode.com/problems/minimum-number-of-operations-to-reinitialize-a-permutation
Medium
793 Array, Greedy https://leetcode.com/problems/add-minimum-number-of-rungs Medium
Array, Hash Table, Math, Counting,
794 Number Theory https://leetcode.com/problems/number-of-pairs-of-interchangeable-rectangles Medium
795 Array, String https://leetcode.com/problems/number-of-pairs-of-strings-with-concatenation-equal-to-target
Medium
796 Array, Math https://leetcode.com/problems/four-divisors Medium
797 Array, Greedy, String Matching https://leetcode.com/problems/form-array-by-concatenating-subarrays-of-another-array
Medium
798 Array, Math, Simulation https://leetcode.com/problems/find-missing-observations Medium
Array, Hash Table, String, Sorting,
799 Ordered Set https://leetcode.com/problems/display-table-of-food-orders-in-a-restaurant Medium
800 Math, Binary Search https://leetcode.com/problems/minimum-garden-perimeter-to-collect-enough-apples
Medium
801 Array, Hash Table, Design, Counting https://leetcode.com/problems/detect-squares Medium
802 Linked List https://leetcode.com/problems/find-the-minimum-and-maximum-number-of-nodes-between-critical-points
Medium
803 Array, Sliding Window https://leetcode.com/problems/k-radius-subarray-averages Medium
804 Array, Matrix, Prefix Sum https://leetcode.com/problems/largest-magic-square Medium
Hash Table, Tree, Breadth-First
805 Search, Design https://leetcode.com/problems/operations-on-tree Medium
806 Two Pointers, String https://leetcode.com/problems/magical-string Medium
807 Math, Stack, Simulation https://leetcode.com/problems/clumsy-factorial Medium
808 Array, Greedy https://leetcode.com/problems/previous-permutation-with-one-swap Medium
Hash Table, Tree, Depth-First Search,
809 Design https://leetcode.com/problems/throne-inheritance Medium
810 Array, Backtracking, Bit Manipulation https://leetcode.com/problems/count-number-of-maximum-bitwise-or-subsets Medium
811 Math https://leetcode.com/problems/closest-divisors Medium
812 Array, Greedy, Sorting https://leetcode.com/problems/maximum-element-after-decreasing-and-rearrangingMedium
813 Array, String, Simulation https://leetcode.com/problems/adding-spaces-to-a-string Medium
814 Math, String, Greedy, Game Theory https://leetcode.com/problems/remove-colored-pieces-if-both-neighbors-are-the-same-color
Medium
815 Array, Simulation https://leetcode.com/problems/count-unhappy-friends Medium
Array, Heap (Priority Queue),
816 Simulation https://leetcode.com/problems/number-of-orders-in-the-backlog Medium
817 Array, Matrix, Simulation https://leetcode.com/problems/cyclically-rotating-a-grid Medium
818 String, Simulation https://leetcode.com/problems/execution-of-all-suffix-instructions-staying-in-a-grid
Medium
819 Array, Hash Table, String, Sorting https://leetcode.com/problems/alert-using-same-key-card-three-or-more-times-in-a-one-hour-period
Medium
820 Math, Brainteaser https://leetcode.com/problems/moving-stones-until-consecutive Medium
821 Math, String https://leetcode.com/problems/the-number-of-full-rounds-you-have-played Medium
822 Array, Sorting https://leetcode.com/problems/widest-vertical-area-between-two-points-containing-no-points
Medium
823 Math, Greedy https://leetcode.com/problems/max-difference-you-can-get-from-changing-an-integerMedium
824 Array, Greedy https://leetcode.com/problems/minimum-elements-to-add-to-form-a-given-sum Medium
825 Hash Table, String https://leetcode.com/problems/html-entity-parser Medium
826 Hash Table, Design https://leetcode.com/problems/design-authentication-manager Medium
827 Divide and Conquer, Tree https://leetcode.com/problems/logical-or-of-two-binary-grids-represented-as-quad-trees
Medium
Tree, Depth-First Search, Breadth-First
828 Search, Binary Tree https://leetcode.com/problems/print-binary-tree Medium
829 Array, String, Greedy https://leetcode.com/problems/largest-number-after-mutating-substring Medium
830 Array, Greedy https://leetcode.com/problems/minimum-number-of-people-to-teach Medium
Array, Math, Sorting, Heap (Priority
831 Queue), Matrix, Prefix Sum https://leetcode.com/problems/get-biggest-three-rhombus-sums-in-a-grid Medium
832 Simulation https://leetcode.com/problems/incremental-memory-leak Medium
833 String, Simulation https://leetcode.com/problems/decode-the-slanted-ciphertext Medium
Array, Math, Greedy, Counting, Game
834 Theory https://leetcode.com/problems/stone-game-ix Medium
835 Array, Matrix, Enumeration https://leetcode.com/problems/check-if-word-can-be-placed-in-crossword Medium
836 String https://leetcode.com/problems/masking-personal-information Medium
837 Linked List https://leetcode.com/problems/reverse-nodes-in-even-length-groups Medium
838 Array, Hash Table, Design https://leetcode.com/problems/apply-discount-every-n-orders Medium
839 Array, Hash Table https://leetcode.com/problems/card-flipping-game Medium
840 Design, Simulation https://leetcode.com/problems/walking-robot-simulation-ii Medium
841 https://leetcode.com/problems/destroying-asteroids Medium
842 https://leetcode.com/problems/number-of-laser-beams-in-a-bank Medium
843 Math, Greedy, Recursion https://leetcode.com/problems/minimum-non-zero-product-of-the-array-elementsMedium
Hash Table, Binary Search, Design,
844 Sorting, Ordered Set https://leetcode.com/problems/tweet-counts-per-frequency Medium
845 Math, Backtracking, Enumeration https://leetcode.com/problems/next-greater-numerically-balanced-number Medium
846 Array, Hash Table, Design, Simulation https://leetcode.com/problems/simple-bank-system Medium
847 Array, Two Pointers, Simulation https://leetcode.com/problems/watering-plants-ii Medium
848 Array, Prefix Sum https://leetcode.com/problems/can-you-eat-your-favorite-candy-on-your-favorite-day
Medium
849 Array, Matrix, Enumeration https://leetcode.com/problems/check-if-move-is-legal Medium
850 Array, Matrix https://leetcode.com/problems/image-overlap Medium
851 Array, Simulation https://leetcode.com/problems/maximum-profit-of-operating-a-centennial-wheel Medium
852 Array, Enumeration https://leetcode.com/problems/coordinate-with-maximum-network-quality Medium
853 Array, Math https://leetcode.com/problems/escape-the-ghosts Medium
854 Array, Simulation https://leetcode.com/problems/walking-robot-simulation Medium
Math, Two Pointers, Probability and
855 Statistics https://leetcode.com/problems/statistics-from-a-large-sample Medium
Math, Bit Manipulation, Depth-First
856 Search, Breadth-First Search https://leetcode.com/problems/bulb-switcher-ii Medium
 Crack The Coding Interview - Dinesh Varyani
https://www.youtube.com/user/hubberspot?sub_confirmation=1

# Topic Question Difficulty

Array, Two Pointers, Dynamic

1 Programming, Stack, Monotonic Stack https://leetcode.com/problems/trapping-rain-water Hard
Array, Binary Search, Divide and
2 Conquer https://leetcode.com/problems/median-of-two-sorted-arrays Hard
Linked List, Divide and Conquer, Heap
3 (Priority Queue), Merge Sort https://leetcode.com/problems/merge-k-sorted-lists Hard
4 Hash Table, String, Sliding Window https://leetcode.com/problems/minimum-window-substring Hard
Array, Queue, Sliding Window, Heap
5 (Priority Queue), Monotonic Queue https://leetcode.com/problems/sliding-window-maximum Hard
6 Array, Stack, Monotonic Stack https://leetcode.com/problems/largest-rectangle-in-histogram Hard
7 Array, Hash Table https://leetcode.com/problems/first-missing-positive Hard
Dynamic Programming, Tree, Depth-
8 First Search, Binary Tree https://leetcode.com/problems/binary-tree-maximum-path-sum Hard
9 String, Dynamic Programming https://leetcode.com/problems/edit-distance Hard
String, Dynamic Programming,
10 Recursion https://leetcode.com/problems/regular-expression-matching Hard
11 String, Dynamic Programming, Stack https://leetcode.com/problems/longest-valid-parentheses Hard
Hash Table, String, Breadth-First
12 Search https://leetcode.com/problems/word-ladder Hard
Two Pointers, Design, Sorting, Heap
13 (Priority Queue), Data Stream https://leetcode.com/problems/find-median-from-data-stream Hard
Array, Dynamic Programming, Stack,
14 Matrix, Monotonic Stack https://leetcode.com/problems/maximal-rectangle Hard
15 Linked List, Recursion https://leetcode.com/problems/reverse-nodes-in-k-group Hard
String, Tree, Depth-First Search,
Breadth-First Search, Design, Binary
16 Tree https://leetcode.com/problems/serialize-and-deserialize-binary-tree Hard
17 Array, Dynamic Programming https://leetcode.com/problems/burst-balloons Hard
Array, String, Backtracking, Trie,
18 Matrix https://leetcode.com/problems/word-search-ii Hard
19 Array, Dynamic Programming https://leetcode.com/problems/best-time-to-buy-and-sell-stock-iii Hard
Array, Binary Search, Divide and
Conquer, Binary Indexed Tree,
Segment Tree, Merge Sort, Ordered
20 Set https://leetcode.com/problems/count-of-smaller-numbers-after-self Hard
21 Array, Backtracking https://leetcode.com/problems/n-queens Hard
Dynamic Programming, Depth-First
Search, Breadth-First Search, Graph,
22 Topological Sort, Memoization https://leetcode.com/problems/longest-increasing-path-in-a-matrix Hard
23 Array, Backtracking, Matrix https://leetcode.com/problems/sudoku-solver Hard
String, Backtracking, Breadth-First
24 Search https://leetcode.com/problems/remove-invalid-parentheses Hard
Hash Table, String, Dynamic
Programming, Backtracking, Trie,
25 Memoization https://leetcode.com/problems/word-break-ii Hard
String, Dynamic Programming,
26 Greedy, Recursion https://leetcode.com/problems/wildcard-matching Hard
Array, Binary Search, Dynamic
27 Programming, Greedy https://leetcode.com/problems/split-array-largest-sum Hard
28 Array, Dynamic Programming, Matrix https://leetcode.com/problems/dungeon-game Hard
Depth-First Search, Graph, Eulerian
29 Circuit https://leetcode.com/problems/reconstruct-itinerary Hard
Array, Divide and Conquer, Binary
Indexed Tree, Segment Tree, Line
Sweep, Heap (Priority Queue), Ordered
30 Set https://leetcode.com/problems/the-skyline-problem Hard
31 Array, Dynamic Programming https://leetcode.com/problems/best-time-to-buy-and-sell-stock-iv Hard
Hash Table, String, Backtracking,
32 Breadth-First Search https://leetcode.com/problems/word-ladder-ii Hard
Depth-First Search, Graph,
33 Biconnected Component https://leetcode.com/problems/critical-connections-in-a-network Hard
34 Math, String, Stack, Recursion https://leetcode.com/problems/basic-calculator Hard
35 Math, Recursion https://leetcode.com/problems/permutation-sequence Hard
36 String, Dynamic Programming https://leetcode.com/problems/distinct-subsequences Hard
37 String, Dynamic Programming https://leetcode.com/problems/palindrome-partitioning-ii Hard
Hash Table, Linked List, Design,
38 Doubly-Linked List https://leetcode.com/problems/lfu-cache Hard
Array, Binary Search, Dynamic
39 Programming, Sorting https://leetcode.com/problems/russian-doll-envelopes Hard
Array, Binary Search, Dynamic
40 Programming, Sorting https://leetcode.com/problems/maximum-profit-in-job-scheduling Hard
 Array, Hash Table, Sliding Window,
41 Counting https://leetcode.com/problems/subarrays-with-k-different-integers Hard
Array, Binary Search, Queue, Sliding
Window, Heap (Priority Queue), Prefix
42 Sum, Monotonic Queue https://leetcode.com/problems/shortest-subarray-with-sum-at-least-k Hard
43 Array, Binary Search https://leetcode.com/problems/find-minimum-in-rotated-sorted-array-ii Hard
Array, Backtracking, Bit Manipulation,
44 Matrix https://leetcode.com/problems/unique-paths-iii Hard
Hash Table, Tree, Depth-First Search,
45 Breadth-First Search, Binary Tree https://leetcode.com/problems/vertical-order-traversal-of-a-binary-tree Hard
46 Array, Greedy https://leetcode.com/problems/candy Hard
47 Array, Hash Table, String, Trie https://leetcode.com/problems/palindrome-pairs Hard
Array, Breadth-First Search, Heap
48 (Priority Queue), Matrix https://leetcode.com/problems/trapping-rain-water-ii Hard
Hash Table, Stack, Design, Ordered
49 Set https://leetcode.com/problems/maximum-frequency-stack Hard
Dynamic Programming, Tree, Depth-
50 First Search, Binary Tree https://leetcode.com/problems/binary-tree-cameras Hard
51 Math, String, Backtracking https://leetcode.com/problems/expression-add-operators Hard
Array, Binary Search, Divide and
Conquer, Binary Indexed Tree,
Segment Tree, Merge Sort, Ordered
52 Set https://leetcode.com/problems/reverse-pairs Hard
Dynamic Programming, Tree, Depth-
53 First Search, Graph https://leetcode.com/problems/sum-of-distances-in-tree Hard
Array, Dynamic Programming, Greedy,
54 Heap (Priority Queue) https://leetcode.com/problems/minimum-number-of-refueling-stops Hard
55 Array, Dynamic Programming, Matrix https://leetcode.com/problems/cherry-pickup Hard
String, Rolling Hash, String Matching,
56 Hash Function https://leetcode.com/problems/shortest-palindrome Hard
57 Array, Dynamic Programming https://leetcode.com/problems/frog-jump Hard
Math, Binary Search, Dynamic
58 Programming https://leetcode.com/problems/super-egg-drop Hard
Array, Depth-First Search, Breadth-
59 First Search, Union Find, Matrix https://leetcode.com/problems/making-a-large-island Hard
Array, Hash Table, Sliding Window,
60 Heap (Priority Queue) https://leetcode.com/problems/sliding-window-median Hard
61 Array, Dynamic Programming https://leetcode.com/problems/minimum-swaps-to-make-sequences-increasing Hard
Array, Hash Table, Greedy, Sliding
Window, Sorting, Heap (Priority
62 Queue) https://leetcode.com/problems/smallest-range-covering-elements-from-k-lists Hard
63 Math, String, Recursion https://leetcode.com/problems/integer-to-english-words Hard
64 Array, Sorting, Bucket Sort, Radix Sort https://leetcode.com/problems/maximum-gap Hard
Array, Binary Search, Dynamic
65 Programming, Matrix, Ordered Set https://leetcode.com/problems/max-sum-of-rectangle-no-larger-than-k Hard
66 String, Dynamic Programming https://leetcode.com/problems/shortest-common-supersequence Hard
67 Array, Greedy, Heap (Priority Queue) https://leetcode.com/problems/course-schedule-iii Hard
Array, Two Pointers, Binary Search,
68 Sorting https://leetcode.com/problems/find-k-th-smallest-pair-distance Hard
69 Array, Breadth-First Search, Matrix https://leetcode.com/problems/shortest-path-in-a-grid-with-obstacles-eliminationHard
Array, String, Dynamic Programming,
70 Depth-First Search, Trie https://leetcode.com/problems/concatenated-words Hard
71 Hash Table, String, Sliding Window https://leetcode.com/problems/substring-with-concatenation-of-all-words Hard
Array, Hash Table, Breadth-First
72 Search https://leetcode.com/problems/bus-routes Hard
Array, Binary Search, Depth-First
Search, Breadth-First Search, Union
73 Find, Heap (Priority Queue), Matrix https://leetcode.com/problems/swim-in-rising-water Hard
String, Binary Search, Sliding Window,
Rolling Hash, Suffix Array, Hash
74 Function https://leetcode.com/problems/longest-duplicate-substring Hard
75 Array, Dynamic Programming https://leetcode.com/problems/maximum-sum-of-3-non-overlapping-subarrays Hard
76 Array, String, Simulation https://leetcode.com/problems/text-justification Hard
77 Binary Search https://leetcode.com/problems/kth-smallest-number-in-multiplication-table Hard
Array, Greedy, Sorting, Heap (Priority
78 Queue) https://leetcode.com/problems/minimum-cost-to-hire-k-workers Hard
Array, Hash Table, Math, Design,
79 Randomized https://leetcode.com/problems/insert-delete-getrandom-o1-duplicates-allowed Hard
Greedy, Depth-First Search, Breadth-
80 First Search, Union Find, Graph https://leetcode.com/problems/couples-holding-hands Hard
81 Array, Hash Table, Matrix, Prefix Sum https://leetcode.com/problems/number-of-submatrices-that-sum-to-target Hard
Array, String, Design, Trie, Data
82 Stream https://leetcode.com/problems/stream-of-characters Hard
Depth-First Search, Breadth-First
83 Search, Union Find, Graph https://leetcode.com/problems/redundant-connection-ii Hard
84 Backtracking https://leetcode.com/problems/n-queens-ii Hard
 Array, Dynamic Programming,
85 Memoization https://leetcode.com/problems/remove-boxes Hard
86 Array, Dynamic Programming https://leetcode.com/problems/minimum-cost-to-merge-stones Hard
Array, Binary Search, Divide and
Conquer, Binary Indexed Tree,
Segment Tree, Merge Sort, Ordered
87 Set https://leetcode.com/problems/count-of-range-sum Hard
88 String, Dynamic Programming https://leetcode.com/problems/minimum-insertion-steps-to-make-a-string-palindrome
Hard
89 Array, Breadth-First Search, Matrix https://leetcode.com/problems/sliding-puzzle Hard
90 Array, Dynamic Programming, Greedy https://leetcode.com/problems/minimum-number-of-taps-to-open-to-water-a-garden
Hard
Dynamic Programming, Bit
Manipulation, Breadth-First Search,
91 Graph, Bitmask https://leetcode.com/problems/shortest-path-visiting-all-nodes Hard
92 String, Dynamic Programming https://leetcode.com/problems/scramble-string Hard
Array, Dynamic Programming, Stack,
93 Monotonic Stack, Ordered Set https://leetcode.com/problems/odd-even-jump Hard
94 Array, Dynamic Programming https://leetcode.com/problems/arithmetic-slices-ii-subsequence Hard
95 Stack, Greedy, Monotonic Stack https://leetcode.com/problems/create-maximum-number Hard
96 Array, Math, Union Find https://leetcode.com/problems/largest-component-size-by-common-factor Hard
97 String, Dynamic Programming https://leetcode.com/problems/count-different-palindromic-subsequences Hard
Array, Math, String, Interactive, Game
98 Theory https://leetcode.com/problems/guess-the-word Hard
99 Array, Math, Backtracking https://leetcode.com/problems/24-game Hard
Array, Greedy, Sorting, Heap (Priority
100 Queue) https://leetcode.com/problems/maximum-performance-of-a-team Hard
101 Array, Greedy https://leetcode.com/problems/patching-array Hard
102 Array, Dynamic Programming, Matrix https://leetcode.com/problems/cherry-pickup-ii Hard
103 Array, Dynamic Programming https://leetcode.com/problems/minimum-difficulty-of-a-job-schedule Hard
Array, Math, Binary Search, Dynamic
104 Programming https://leetcode.com/problems/numbers-at-most-n-given-digit-set Hard
Array, Hash Table, String, Bit
105 Manipulation, Trie https://leetcode.com/problems/number-of-valid-words-for-each-puzzle Hard
106 Dynamic Programming https://leetcode.com/problems/non-negative-integers-without-consecutive-ones Hard
107 Dynamic Programming https://leetcode.com/problems/student-attendance-record-ii Hard
Hash Table, Linked List, Design,
108 Doubly-Linked List https://leetcode.com/problems/all-oone-data-structure Hard
Array, Stack, Greedy, Sorting,
109 Monotonic Stack https://leetcode.com/problems/max-chunks-to-make-sorted-ii Hard
110 String, Dynamic Programming https://leetcode.com/problems/decode-ways-ii Hard
111 String, Dynamic Programming https://leetcode.com/problems/distinct-subsequences-ii Hard
112 String, Dynamic Programming https://leetcode.com/problems/count-unique-characters-of-all-substrings-of-a-given-string
Hard
Array, String, Dynamic Programming,
113 Bit Manipulation, Bitmask https://leetcode.com/problems/find-the-shortest-superstring Hard
114 Array, Binary Search, Interactive https://leetcode.com/problems/find-in-mountain-array Hard
String, Tree, Depth-First Search,
115 Binary Tree https://leetcode.com/problems/recover-a-tree-from-preorder-traversal Hard
116 String, Design, Trie https://leetcode.com/problems/prefix-and-suffix-search Hard
Array, Hash Table, Breadth-First
117 Search https://leetcode.com/problems/jump-game-iv Hard
118 Array, Dynamic Programming https://leetcode.com/problems/minimum-cost-to-cut-a-stick Hard
119 Math, Binary Search https://leetcode.com/problems/nth-magical-number Hard
120 Math, Enumeration https://leetcode.com/problems/consecutive-numbers-sum Hard
Array, Breadth-First Search, Graph,
Heap (Priority Queue), Matrix, Shortest
121 Path https://leetcode.com/problems/minimum-cost-to-make-at-least-one-valid-path-in-a-grid
Hard
122 Math https://leetcode.com/problems/reaching-points Hard
123 Dynamic Programming https://leetcode.com/problems/count-vowels-permutation Hard
Dynamic Programming, Tree, Depth-
First Search, Binary Search Tree,
124 Binary Tree https://leetcode.com/problems/maximum-sum-bst-in-binary-tree Hard
Array, Math, Dynamic Programming,
125 Game Theory https://leetcode.com/problems/stone-game-iii Hard
126 Design, Segment Tree, Ordered Set https://leetcode.com/problems/range-module Hard
127 Hash Table, String, Stack https://leetcode.com/problems/number-of-atoms Hard
Binary Search, Dynamic Programming,
Tree, Depth-First Search, Breadth-First
128 Search, Design https://leetcode.com/problems/kth-ancestor-of-a-tree-node Hard
Array, Breadth-First Search, Heap
129 (Priority Queue), Matrix https://leetcode.com/problems/cut-off-trees-for-golf-event Hard
130 Dynamic Programming https://leetcode.com/problems/race-car Hard
Array, Dynamic Programming, Greedy,
131 Sorting https://leetcode.com/problems/reducing-dishes Hard
132 String, Breadth-First Search https://leetcode.com/problems/k-similar-strings Hard
Array, Binary Search, Heap (Priority
133 Queue), Matrix https://leetcode.com/problems/find-the-kth-smallest-sum-of-a-matrix-with-sorted-rows
Hard
 Array, Segment Tree, Line Sweep,
134 Ordered Set https://leetcode.com/problems/rectangle-area-ii Hard
Array, Math, Dynamic Programming,
135 Bit Manipulation, Bitmask https://leetcode.com/problems/split-array-with-same-average Hard
136 String, Dynamic Programming https://leetcode.com/problems/strange-printer Hard
Array, Dynamic Programming, Stack,
137 Greedy, Monotonic Stack https://leetcode.com/problems/minimum-number-of-increments-on-subarrays-to-form-a-target-array
Hard
138 Dynamic Programming https://leetcode.com/problems/k-inverse-pairs-array Hard
139 Hash Table, Math, Geometry https://leetcode.com/problems/max-points-on-a-line Hard
Array, Queue, Sliding Window, Heap
140 (Priority Queue), Monotonic Queue https://leetcode.com/problems/max-value-of-equation Hard
141 Array, Union Find, Matrix https://leetcode.com/problems/bricks-falling-when-hit Hard
142 Bit Manipulation, Breadth-First Search https://leetcode.com/problems/shortest-path-to-get-all-keys Hard
Array, Bit Manipulation, Sliding
143 Window, Prefix Sum https://leetcode.com/problems/minimum-number-of-k-consecutive-bit-flips Hard
144 String, Dynamic Programming https://leetcode.com/problems/minimum-distance-to-type-a-word-using-two-fingers
Hard
145 Dynamic Programming https://leetcode.com/problems/number-of-ways-to-paint-n-3-grid Hard
String, Depth-First Search, Breadth-
146 First Search, Union Find https://leetcode.com/problems/similar-string-groups Hard
Array, Greedy, Sorting, Heap (Priority
147 Queue) https://leetcode.com/problems/ipo Hard
Array, Dynamic Programming, Queue,
Sliding Window, Heap (Priority Queue),
148 Monotonic Queue https://leetcode.com/problems/constrained-subsequence-sum Hard
Array, Binary Search, Heap (Priority
149 Queue) https://leetcode.com/problems/k-th-smallest-prime-fraction Hard
150 Array, Math https://leetcode.com/problems/three-equal-parts Hard
151 Design, Segment Tree, Ordered Set https://leetcode.com/problems/my-calendar-iii Hard
Dynamic Programming, Backtracking,
152 Bit Manipulation, Bitmask https://leetcode.com/problems/stickers-to-spell-word Hard
Math, Dynamic Programming,
153 Combinatorics https://leetcode.com/problems/number-of-music-playlists Hard
Array, Dynamic Programming, Bit
154 Manipulation, Bitmask https://leetcode.com/problems/smallest-sufficient-team Hard
String, Dynamic Programming, Depth-
155 First Search, Breadth-First Search https://leetcode.com/problems/freedom-trail Hard
156 Array, Dynamic Programming https://leetcode.com/problems/dice-roll-simulation Hard
157 String, Dynamic Programming https://leetcode.com/problems/palindrome-partitioning-iii Hard
158 Array, Heap (Priority Queue) https://leetcode.com/problems/construct-target-array-with-multiple-sums Hard
159 Array, Dynamic Programming, Matrix https://leetcode.com/problems/minimum-falling-path-sum-ii Hard
Array, Math, Dynamic Programming,
160 Sorting https://leetcode.com/problems/allocate-mailboxes Hard
Math, Dynamic Programming,
161 Combinatorics https://leetcode.com/problems/poor-pigs Hard
Array, Math, Dynamic Programming,
Backtracking, Bit Manipulation,
162 Bitmask https://leetcode.com/problems/number-of-squareful-arrays Hard
Math, Dynamic Programming,
163 Recursion https://leetcode.com/problems/number-of-digit-one Hard
164 Array, Dynamic Programming https://leetcode.com/problems/tallest-billboard Hard
165 Dynamic Programming, Memoization https://leetcode.com/problems/minimum-number-of-days-to-eat-n-oranges Hard
Math, Dynamic Programming, Breadth-
First Search, Graph, Memoization,
166 Game Theory https://leetcode.com/problems/cat-and-mouse Hard
167 Binary Search, Design, Ordered Set https://leetcode.com/problems/data-stream-as-disjoint-intervals Hard
Array, Breadth-First Search, Heap
168 (Priority Queue), Matrix https://leetcode.com/problems/minimum-moves-to-move-a-box-to-their-target-location
Hard
169 Array, Dynamic Programming, Sorting https://leetcode.com/problems/jump-game-v Hard
170 Array, Line Sweep https://leetcode.com/problems/perfect-rectangle Hard
String, Rolling Hash, String Matching,
171 Hash Function https://leetcode.com/problems/longest-happy-prefix Hard
Array, Binary Search, Dynamic
172 Programming, Greedy https://leetcode.com/problems/minimum-number-of-removals-to-make-mountain-array
Hard
Array, Binary Search, Dynamic
173 Programming https://leetcode.com/problems/make-array-strictly-increasing Hard
Hash Table, Math, Binary Search,
174 Sorting, Randomized https://leetcode.com/problems/random-pick-with-blacklist Hard
Array, Depth-First Search, Breadth-
175 First Search, Union Find, Matrix https://leetcode.com/problems/minimize-malware-spread Hard
Array, Greedy, Union Find, Graph,
176 Topological Sort, Matrix https://leetcode.com/problems/rank-transform-of-a-matrix Hard
Depth-First Search, Breadth-First
177 Search, Graph, Topological Sort https://leetcode.com/problems/sort-items-by-groups-respecting-dependencies Hard
178 String, Stack, Recursion https://leetcode.com/problems/parsing-a-boolean-expression Hard
179 Array, Stack, Monotonic Stack https://leetcode.com/problems/number-of-visible-people-in-a-queue Hard
 Array, String, Dynamic Programming,
Backtracking, Bit Manipulation,
180 Bitmask https://leetcode.com/problems/maximum-score-words-formed-by-letters Hard
Math, Dynamic Programming, Game
181 Theory https://leetcode.com/problems/stone-game-iv Hard
Array, Dynamic Programming, Bit
182 Manipulation, Bitmask https://leetcode.com/problems/number-of-ways-to-wear-different-hats-to-each-other
Hard
183 Array, Math, Geometry https://leetcode.com/problems/erect-the-fence Hard
184 Array, Dynamic Programming https://leetcode.com/problems/max-dot-product-of-two-subsequences Hard
185 Math, String, Sorting https://leetcode.com/problems/orderly-queue Hard
Dynamic Programming, Bit
186 Manipulation, Graph, Bitmask https://leetcode.com/problems/parallel-courses-ii Hard
Array, Dynamic Programming, Bit
187 Manipulation, Matrix, Bitmask https://leetcode.com/problems/maximum-students-taking-exam Hard
Array, Math, Stack, Heap (Priority
188 Queue), Monotonic Stack https://leetcode.com/problems/car-fleet-ii Hard
189 Union Find, Graph https://leetcode.com/problems/remove-max-number-of-edges-to-keep-graph-fully-traversable
Hard
190 Trie https://leetcode.com/problems/k-th-smallest-in-lexicographical-order Hard
191 String, Stack, Greedy, Queue https://leetcode.com/problems/stamping-the-sequence Hard
Array, Greedy, Heap (Priority Queue),
192 Ordered Set https://leetcode.com/problems/minimize-deviation-in-array Hard
Array, Two Pointers, Dynamic
193 Programming, Greedy https://leetcode.com/problems/get-the-maximum-score Hard
194 String, Recursion https://leetcode.com/problems/special-binary-string Hard
195 Array, Greedy https://leetcode.com/problems/super-washing-machines Hard
Array, Dynamic Programming, Greedy,
196 Heap (Priority Queue) https://leetcode.com/problems/pizza-with-3n-slices Hard
197 Dynamic Programming https://leetcode.com/problems/number-of-ways-to-stay-in-the-same-place-after-some-steps
Hard
Graph, Heap (Priority Queue), Shortest
198 Path https://leetcode.com/problems/reachable-nodes-in-subdivided-graph Hard
199 Array, Dynamic Programming https://leetcode.com/problems/paint-house-iii Hard
Array, Two Pointers, Binary Search,
200 Stack, Monotonic Stack https://leetcode.com/problems/maximum-score-of-a-good-subarray Hard
201 Hash Table, String, Bit Manipulation https://leetcode.com/problems/find-longest-awesome-substring Hard
Array, Bit Manipulation, Breadth-First
202 Search, Matrix https://leetcode.com/problems/minimum-number-of-flips-to-convert-binary-matrix-to-zero-matrix
Hard
203 Array, Dynamic Programming https://leetcode.com/problems/form-largest-integer-with-digits-that-add-up-to-target
Hard
Math, Dynamic Programming,
204 Combinatorics https://leetcode.com/problems/count-all-valid-pickup-and-delivery-options Hard
205 Math, String https://leetcode.com/problems/find-the-closest-palindrome Hard
206 String, Greedy, Heap (Priority Queue) https://leetcode.com/problems/strong-password-checker Hard
Array, Binary Search, Divide and
Conquer, Binary Indexed Tree,
Segment Tree, Merge Sort, Ordered
207 Set https://leetcode.com/problems/create-sorted-array-through-instructions Hard
208 Array, Math, Sorting https://leetcode.com/problems/sum-of-subsequence-widths Hard
209 Dynamic Programming https://leetcode.com/problems/valid-permutations-for-di-sequence Hard
Array, Dynamic Programming,
Backtracking, Bit Manipulation,
210 Bitmask https://leetcode.com/problems/find-minimum-time-to-finish-all-jobs Hard
211 String, Greedy https://leetcode.com/problems/maximum-number-of-non-overlapping-substringsHard
212 Array, Greedy, Sorting https://leetcode.com/problems/set-intersection-size-at-least-two Hard
Array, Binary Search, Design, Binary
213 Indexed Tree, Segment Tree https://leetcode.com/problems/online-majority-element-in-subarray Hard
214 Array, Segment Tree, Ordered Set https://leetcode.com/problems/falling-squares Hard
215 Two Pointers, String https://leetcode.com/problems/last-substring-in-lexicographical-order Hard
216 Array, Union Find, Graph, Sorting https://leetcode.com/problems/checking-existence-of-edge-length-limited-paths Hard
Array, Hash Table, Depth-First Search,
217 Breadth-First Search https://leetcode.com/problems/escape-a-large-maze Hard
218 Dynamic Programming, Backtracking https://leetcode.com/problems/tiling-a-rectangle-with-the-fewest-squares Hard
219 String, Dynamic Programming https://leetcode.com/problems/string-compression-ii Hard
Math, Dynamic Programming,
220 Combinatorics https://leetcode.com/problems/number-of-ways-to-rearrange-sticks-with-k-sticks-visible
Hard
221 Array, Dynamic Programming, Sorting https://leetcode.com/problems/maximum-height-by-stacking-cuboids Hard
Array, Dynamic Programming,
222 Memoization, Matrix https://leetcode.com/problems/number-of-ways-of-cutting-a-pizza Hard
223 String, Dynamic Programming https://leetcode.com/problems/palindrome-partitioning-iv Hard
224 Array, String, Dynamic Programming https://leetcode.com/problems/delete-columns-to-make-sorted-iii Hard
Union Find, Graph, Sorting, Minimum
Spanning Tree, Strongly Connected
225 Component https://leetcode.com/problems/find-critical-and-pseudo-critical-edges-in-minimum-spanning-tree
Hard
226 String https://leetcode.com/problems/valid-number Hard
227 Array, Dynamic Programming https://leetcode.com/problems/profitable-schemes Hard
 Two Pointers, String, Dynamic
Programming, Greedy, Rolling Hash,
228 Hash Function https://leetcode.com/problems/longest-chunked-palindrome-decomposition Hard
Array, Binary Search, Dynamic
229 Programming https://leetcode.com/problems/maximum-number-of-events-that-can-be-attended-ii
Hard
230 Dynamic Programming https://leetcode.com/problems/build-array-where-you-can-find-the-maximum-exactly-k-comparisons
Hard
Array, Depth-First Search, Breadth-
231 First Search, Union Find, Matrix https://leetcode.com/problems/minimize-malware-spread-ii Hard
Array, Two Pointers, Dynamic
Programming, Bit Manipulation,
232 Bitmask https://leetcode.com/problems/closest-subsequence-sum Hard
233 Hash Table, String, Stack, Recursion https://leetcode.com/problems/parse-lisp-expression Hard
Hash Table, Dynamic Programming,
Graph, Topological Sort, Memoization,
234 Counting https://leetcode.com/problems/largest-color-value-in-a-directed-graph Hard
235 Array, Binary Search https://leetcode.com/problems/minimum-operations-to-make-the-array-k-increasing
Hard
236 Math, Dynamic Programming https://leetcode.com/problems/numbers-with-repeated-digits Hard
Array, Binary Search, Depth-First
Search, Breadth-First Search, Union
237 Find, Matrix https://leetcode.com/problems/last-day-where-you-can-still-cross Hard
238 Dynamic Programming, Graph https://leetcode.com/problems/minimum-cost-to-reach-destination-in-time Hard
Array, Greedy, Sliding Window, Prefix
239 Sum https://leetcode.com/problems/minimum-adjacent-swaps-for-k-consecutive-onesHard
240 Array, Hash Table https://leetcode.com/problems/grid-illumination Hard
Array, Hash Table, Binary Search,
241 Greedy https://leetcode.com/problems/minimum-operations-to-make-a-subsequence Hard
Array, Math, Divide and Conquer,
Dynamic Programming, Tree, Union
Find, Binary Search Tree,
Memoization, Combinatorics, Binary
242 Tree https://leetcode.com/problems/number-of-ways-to-reorder-array-to-get-same-bstHard
243 Array, Dynamic Programming, Greedy https://leetcode.com/problems/largest-multiple-of-three Hard
244 Linked List, Design https://leetcode.com/problems/design-skiplist Hard
Tree, Depth-First Search, Breadth-First
245 Search, Graph https://leetcode.com/problems/frog-position-after-t-seconds Hard
246 Array, Bit Manipulation, Trie https://leetcode.com/problems/maximum-xor-with-an-element-from-array Hard
String, Backtracking, Stack, Breadth-
247 First Search https://leetcode.com/problems/brace-expansion-ii Hard
Array, Dynamic Programming, Bit
248 Manipulation, Bitmask https://leetcode.com/problems/minimum-xor-sum-of-two-arrays Hard
249 Array, Hash Table https://leetcode.com/problems/maximum-equal-frequency Hard
Array, Depth-First Search, Breadth-
First Search, Matrix, Strongly
250 Connected Component https://leetcode.com/problems/minimum-number-of-days-to-disconnect-island Hard
String, Dynamic Programming,
251 Breadth-First Search, Memoization https://leetcode.com/problems/zuma-game Hard
252 Array, Prefix Sum https://leetcode.com/problems/smallest-rotation-with-highest-score Hard
253 String, Dynamic Programming https://leetcode.com/problems/restore-the-array Hard
Array, Math, Dynamic Programming,
Backtracking, Bit Manipulation,
254 Number Theory, Bitmask https://leetcode.com/problems/maximize-score-after-n-operations Hard
255 Array, Greedy, Sorting https://leetcode.com/problems/minimum-initial-energy-to-finish-tasks Hard
Array, Binary Search, Binary Indexed
256 Tree https://leetcode.com/problems/find-the-longest-valid-obstacle-course-at-each-position
Hard
Array, Math, Geometry, Sliding
257 Window, Sorting https://leetcode.com/problems/maximum-number-of-visible-points Hard
Array, Math, Dynamic Programming,
258 Game Theory https://leetcode.com/problems/stone-game-v Hard
259 String, Greedy, Sorting https://leetcode.com/problems/check-if-string-is-transformable-with-substring-sort-operations
Hard
Array, Dynamic Programming,
260 Memoization https://leetcode.com/problems/count-all-possible-routes Hard
Array, Binary Search, Line Sweep,
261 Sorting, Heap (Priority Queue) https://leetcode.com/problems/minimum-interval-to-include-each-query Hard
262 Array, Dynamic Programming https://leetcode.com/problems/count-number-of-special-subsequences Hard
263 Array, Math, Greedy https://leetcode.com/problems/reverse-subarray-to-maximize-array-value Hard
264 String, Dynamic Programming https://leetcode.com/problems/maximize-palindrome-length-from-subsequences Hard
Depth-First Search, Breadth-First
265 Search, Union Find, Graph, Sorting https://leetcode.com/problems/find-all-people-with-secret Hard
Array, Math, Dynamic Programming,
266 Combinatorics https://leetcode.com/problems/kth-smallest-instructions Hard
Hash Table, Stack, Design, Heap
267 (Priority Queue) https://leetcode.com/problems/dinner-plate-stacks Hard
268 String, Dynamic Programming https://leetcode.com/problems/number-of-unique-good-subsequences Hard
269 Math, Enumeration https://leetcode.com/problems/super-palindromes Hard
Array, Dynamic Programming, Bit
270 Manipulation, Matrix, Bitmask https://leetcode.com/problems/minimum-cost-to-connect-two-groups-of-points Hard
271 Array, Binary Search https://leetcode.com/problems/minimum-number-of-operations-to-make-array-continuous
Hard
 Array, Two Pointers, Binary Search,
Dynamic Programming, Bit
272 Manipulation, Ordered Set, Bitmask https://leetcode.com/problems/partition-array-into-two-arrays-to-minimize-sum-difference
Hard
273 Array, Binary Search, Sorting https://leetcode.com/problems/closest-room Hard
274 Array, Math, Union Find https://leetcode.com/problems/graph-connectivity-with-threshold Hard
275 Array, Dynamic Programming, Matrix https://leetcode.com/problems/number-of-paths-with-max-score Hard
276 Array, Math, String, Backtracking https://leetcode.com/problems/verbal-arithmetic-puzzle Hard
String, Greedy, Binary Indexed Tree,
277 Segment Tree https://leetcode.com/problems/minimum-possible-integer-after-at-most-k-adjacent-swaps-on-digits
Hard
278 Array, Graph, Topological Sort, Matrix https://leetcode.com/problems/strange-printer-ii Hard
279 String, Dynamic Programming https://leetcode.com/problems/count-the-repetitions Hard
280 Array, Math, Bit Manipulation, Matrix https://leetcode.com/problems/transform-to-chessboard Hard
281 Math, Binary Search https://leetcode.com/problems/preimage-size-of-factorial-zeroes-function Hard
282 Array, Math, Binary Search, Prefix Sum https://leetcode.com/problems/sum-of-floored-pairs Hard
283 Dynamic Programming https://leetcode.com/problems/painting-a-grid-with-three-different-colors Hard
Breadth-First Search, Graph, Shortest
284 Path https://leetcode.com/problems/second-minimum-time-to-reach-destination Hard
Array, Greedy, Heap (Priority Queue),
285 Ordered Set https://leetcode.com/problems/find-servers-that-handled-most-number-of-requests
Hard
Dynamic Programming, Bit
286 Manipulation, Memoization https://leetcode.com/problems/minimum-one-bit-operations-to-make-integers-zero
Hard
Dynamic Programming, Bit
Manipulation, Tree, Enumeration,
287 Bitmask https://leetcode.com/problems/count-subtrees-with-max-distance-between-citiesHard
288 Array, Math, Bit Manipulation https://leetcode.com/problems/find-xor-sum-of-all-pairs-bitwise-and Hard
289 https://leetcode.com/problems/maximum-employees-to-be-invited-to-a-meeting Hard
String, Dynamic Programming, String
290 Matching https://leetcode.com/problems/find-all-good-strings Hard
291 Math, Binary Search https://leetcode.com/problems/smallest-good-base Hard
Array, Binary Search, Bit Manipulation,
292 Segment Tree https://leetcode.com/problems/find-a-value-of-a-mysterious-function-closest-to-target
Hard
293 Math, Dynamic Programming https://leetcode.com/problems/least-operators-to-express-number Hard
294 Array, Bit Manipulation, Trie https://leetcode.com/problems/count-pairs-with-xor-in-a-range Hard
Array, Dynamic Programming, Bit
295 Manipulation https://leetcode.com/problems/make-the-xor-of-all-segments-equal-to-zero Hard
Array, Math, Dynamic Programming,
296 Prefix Sum, Game Theory https://leetcode.com/problems/stone-game-viii Hard
297 Union Find, Graph https://leetcode.com/problems/process-restricted-friend-requests Hard
298 Array, Math, Geometry https://leetcode.com/problems/self-crossing Hard
Array, Binary Search, Rolling Hash,
299 Suffix Array, Hash Function https://leetcode.com/problems/longest-common-subpath Hard
Dynamic Programming, Graph,
300 Topological Sort https://leetcode.com/problems/parallel-courses-iii Hard
Dynamic Programming, Tree, Depth-
301 First Search, Union Find https://leetcode.com/problems/smallest-missing-genetic-value-in-each-subtree Hard
302 Array, Math https://leetcode.com/problems/maximum-building-height Hard
303 Math, Design, Segment Tree https://leetcode.com/problems/fancy-sequence Hard
304 Array, Math, Counting, Number Theory https://leetcode.com/problems/number-of-different-subsequences-gcds Hard
Array, Hash Table, Counting,
305 Enumeration, Prefix Sum https://leetcode.com/problems/maximum-number-of-ways-to-partition-an-array Hard
Math, Dynamic Programming, Tree,
Graph, Topological Sort,
306 Combinatorics https://leetcode.com/problems/count-ways-to-build-rooms-in-an-ant-colony Hard
Array, Binary Search, Sorting, Prefix
307 Sum https://leetcode.com/problems/minimum-space-wasted-from-packaging Hard
308 Array, Math, Union Find, Sorting https://leetcode.com/problems/gcd-sort-of-an-array Hard
Array, Dynamic Programming,
Segment Tree, Queue, Heap (Priority
309 Queue), Monotonic Queue https://leetcode.com/problems/delivering-boxes-from-storage-to-ports Hard
310 Array, Hash Table, Bit Manipulation https://leetcode.com/problems/triples-with-bitwise-and-equal-to-zero Hard
311 Array, String, Dynamic Programming https://leetcode.com/problems/number-of-ways-to-form-a-target-string-given-a-dictionary
Hard
312 Array, Math, Number Theory https://leetcode.com/problems/check-if-it-is-a-good-array Hard
Math, Tree, Depth-First Search,
313 Breadth-First Search https://leetcode.com/problems/tree-of-coprimes Hard
314 Bit Manipulation, Enumeration https://leetcode.com/problems/maximum-number-of-achievable-transfer-requestsHard
Array, Binary Search, Sliding Window,
315 Prefix Sum https://leetcode.com/problems/maximum-fruits-harvested-after-at-most-k-steps Hard
Array, Depth-First Search, Breadth-
316 First Search, Matrix, Simulation https://leetcode.com/problems/contain-virus Hard
Array, Dynamic Programming, Bit
317 Manipulation, Memoization, Bitmask https://leetcode.com/problems/maximum-number-of-groups-getting-fresh-donutsHard
Dynamic Programming, Bit
318 Manipulation, Memoization, Bitmask https://leetcode.com/problems/maximize-grid-happiness Hard
319 Array, Bit Manipulation, Trie https://leetcode.com/problems/maximum-genetic-difference-query Hard
320 Math, Binary Search, Greedy https://leetcode.com/problems/building-boxes Hard
321 Array, Binary Search https://leetcode.com/problems/kth-smallest-product-of-two-sorted-arrays Hard
Math, Dynamic Programming,
Backtracking, Combinatorics,
322 Probability and Statistics https://leetcode.com/problems/probability-of-a-two-boxes-having-the-same-number-of-distinct-balls
Hard
323 Two Pointers, Binary Search, Graph https://leetcode.com/problems/count-pairs-of-nodes Hard
Depth-First Search, Graph, Eulerian
324 Circuit https://leetcode.com/problems/valid-arrangement-of-pairs Hard
Array, Dynamic Programming,
Backtracking, Bit Manipulation,
325 Bitmask https://leetcode.com/problems/distribute-repeating-integers Hard
326 Array, Breadth-First Search, Matrix https://leetcode.com/problems/minimum-moves-to-reach-target-with-rotations Hard
Design, Queue, Heap (Priority Queue),
327 Ordered Set https://leetcode.com/problems/finding-mk-average Hard
Hash Table, Binary Search, Tree,
328 Depth-First Search, Binary Tree https://leetcode.com/problems/merge-bsts-to-create-single-bst Hard
329 Array, Dynamic Programming https://leetcode.com/problems/minimum-skips-to-arrive-at-meeting-on-time Hard
330 Array, Backtracking, Graph https://leetcode.com/problems/maximum-path-quality-of-a-graph Hard
String, Dynamic Programming, Suffix
331 Array https://leetcode.com/problems/number-of-ways-to-separate-numbers Hard
String, Stack, Greedy, Monotonic
332 Stack https://leetcode.com/problems/smallest-k-length-subsequence-with-occurrences-of-a-letter
Hard
Array, Math, Dynamic Programming,
333 Bit Manipulation, Bitmask https://leetcode.com/problems/the-number-of-good-subsets Hard
Array, Binary Search, Greedy, Queue,
334 Sorting, Monotonic Queue https://leetcode.com/problems/maximum-number-of-tasks-you-can-assign Hard
335 Array, Breadth-First Search https://leetcode.com/problems/maximum-candies-you-can-get-from-boxes Hard
Array, Dynamic Programming, Bit
336 Manipulation, Bitmask https://leetcode.com/problems/minimum-incompatibility Hard
337 Array, Divide and Conquer https://leetcode.com/problems/find-array-given-subset-sums Hard
338 Math, Geometry, Randomized https://leetcode.com/problems/best-position-for-a-service-centre Hard
339 Graph https://leetcode.com/problems/minimum-degree-of-a-connected-trio-in-a-graph Hard
340 Dynamic Programming, Memoization https://leetcode.com/problems/the-earliest-and-latest-rounds-where-players-compete
Hard
String, Dynamic Programming, Trie,
Sliding Window, Rolling Hash, Hash
341 Function https://leetcode.com/problems/distinct-echo-substrings Hard
Array, Hash Table, Sorting,
342 Enumeration https://leetcode.com/problems/recover-the-original-array Hard
Array, Hash Table, String, Trie, Hash
343 Function https://leetcode.com/problems/delete-duplicate-folders-in-system Hard
String, Backtracking, Greedy,
344 Counting, Enumeration https://leetcode.com/problems/longest-subsequence-repeated-k-times Hard
Math, String, Dynamic Programming,
345 Stack https://leetcode.com/problems/minimum-cost-to-change-the-final-value-of-expression
Hard
346 Array, Math, Dynamic Programming https://leetcode.com/problems/count-ways-to-make-array-with-product Hard
Math, Dynamic Programming, Breadth-
First Search, Graph, Memoization,
347 Game Theory https://leetcode.com/problems/cat-and-mouse-ii Hard
Depth-First Search, Graph, Eulerian
348 Circuit https://leetcode.com/problems/cracking-the-safe Hard
349 Math, Recursion https://leetcode.com/problems/maximize-number-of-nice-divisors Hard
350 Array, Dynamic Programming, Matrix https://leetcode.com/problems/count-fertile-pyramids-in-a-land Hard
Array, Hash Table, Design, Heap
351 (Priority Queue), Ordered Set https://leetcode.com/problems/design-movie-rental-system Hard
352 String, Stack https://leetcode.com/problems/tag-validator Hard
Array, Math, String, Dynamic
353 Programming, Stack, Memoization https://leetcode.com/problems/the-score-of-students-solving-math-expression Hard
354 Math https://leetcode.com/problems/largest-palindrome-product Hard
Array, Math, Bit Manipulation,
355 Brainteaser, Game Theory https://leetcode.com/problems/chalkboard-xor-game Hard
356 Math, String, Combinatorics https://leetcode.com/problems/minimum-number-of-operations-to-make-string-sorted
Hard
Hash Table, Math, String, Stack,
357 Recursion https://leetcode.com/problems/basic-calculator-iv Hard
358 Array, Math, Geometry https://leetcode.com/problems/maximum-number-of-darts-inside-of-a-circular-dartboard
Hard
359 Tree, Graph, Topological Sort https://leetcode.com/problems/number-of-ways-to-reconstruct-a-tree Hard
360 String, Dynamic Programming https://leetcode.com/problems/check-if-an-original-string-exists-given-two-encoded-strings
Hard
361 String, Rolling Hash, Hash Function https://leetcode.com/problems/maximum-product-of-the-length-of-two-palindromic-substrings
Hard
Design, Heap (Priority Queue), Data
362 Stream, Ordered Set https://leetcode.com/problems/sequentially-ordinal-rank-tracker Hard
363 Math, Enumeration https://leetcode.com/problems/sum-of-k-mirror-numbers Hard
364 Math, String https://leetcode.com/problems/equal-rational-numbers Hard
365 Math https://leetcode.com/problems/abbreviating-the-product-of-a-range Hard
366 Array, String, Backtracking, Simulation https://leetcode.com/problems/number-of-valid-move-combinations-on-chessboard
Hard
 Crack The Coding Interview - Dinesh Varyani
https://www.youtube.com/user/hubberspot?sub_confirmation=1

# Topic Question Difficulty

1 Array https://leetcode.com/problems/two-sum Easy

2 Array https://leetcode.com/problems/maximum-subarray Easy
3 Array https://leetcode.com/problems/trapping-rain-water Hard
4 Array https://leetcode.com/problems/3sum Medium
5 Array https://leetcode.com/problems/median-of-two-sorted-arrays Hard
6 Array https://leetcode.com/problems/container-with-most-water Medium
7 Array https://leetcode.com/problems/best-time-to-buy-and-sell-stock Easy
8 Array https://leetcode.com/problems/search-in-rotated-sorted-array Medium
9 Array https://leetcode.com/problems/number-of-islands Medium
10 Array https://leetcode.com/problems/merge-intervals Medium
11 Array https://leetcode.com/problems/find-the-duplicate-number Medium
12 Array https://leetcode.com/problems/product-of-array-except-self Medium
13 Array https://leetcode.com/problems/subarray-sum-equals-k Medium
14 Array https://leetcode.com/problems/house-robber Medium
15 Array https://leetcode.com/problems/longest-increasing-subsequence Medium
16 Array https://leetcode.com/problems/maximum-product-subarray Medium
17 Array https://leetcode.com/problems/coin-change Medium
18 Array https://leetcode.com/problems/jump-game Medium
19 Array https://leetcode.com/problems/find-first-and-last-position-of-element-in-sorted-array
Medium
20 Array https://leetcode.com/problems/permutations Medium
21 Array https://leetcode.com/problems/combination-sum Medium
22 Array https://leetcode.com/problems/sliding-window-maximum Hard
23 Array https://leetcode.com/problems/next-permutation Medium
24 Array https://leetcode.com/problems/sort-colors Medium
25 Array https://leetcode.com/problems/single-number Easy
26 Array https://leetcode.com/problems/largest-rectangle-in-histogram Hard
27 Array https://leetcode.com/problems/first-missing-positive Hard
28 Array https://leetcode.com/problems/word-search Medium
29 Array https://leetcode.com/problems/subsets Medium
30 Array https://leetcode.com/problems/longest-consecutive-sequence Medium
31 Array https://leetcode.com/problems/kth-largest-element-in-an-array Medium
32 Array https://leetcode.com/problems/move-zeroes Easy
33 Array https://leetcode.com/problems/majority-element Easy
34 Array https://leetcode.com/problems/rotate-image Medium
35 Array https://leetcode.com/problems/construct-binary-tree-from-preorder-and-inorder-traversal
Medium
36 Array https://leetcode.com/problems/rotate-array Medium
37 Array https://leetcode.com/problems/top-k-frequent-elements Medium
38 Array https://leetcode.com/problems/jump-game-ii Medium
39 Array https://leetcode.com/problems/partition-equal-subset-sum Medium
40 Array https://leetcode.com/problems/maximal-square Medium
41 Array https://leetcode.com/problems/best-time-to-buy-and-sell-stock-ii Medium
42 Array https://leetcode.com/problems/minimum-path-sum Medium
43 Array https://leetcode.com/problems/search-a-2d-matrix-ii Medium
44 Array https://leetcode.com/problems/search-insert-position Easy
45 Array https://leetcode.com/problems/daily-temperatures Medium
46 Array https://leetcode.com/problems/maximal-rectangle Hard
47 Array https://leetcode.com/problems/task-scheduler Medium
48 Array https://leetcode.com/problems/spiral-matrix Medium
49 Array https://leetcode.com/problems/target-sum Medium
50 Array https://leetcode.com/problems/find-all-numbers-disappeared-in-an-array Easy
51 Array https://leetcode.com/problems/rotting-oranges Medium
52 Array https://leetcode.com/problems/set-matrix-zeroes Medium
53 Array https://leetcode.com/problems/convert-sorted-array-to-binary-search-tree Easy
54 Array https://leetcode.com/problems/search-a-2d-matrix Medium
55 Array https://leetcode.com/problems/find-minimum-in-rotated-sorted-array Medium
56 Array https://leetcode.com/problems/remove-duplicates-from-sorted-array Easy
57 Array https://leetcode.com/problems/minimum-size-subarray-sum Medium
58 Array https://leetcode.com/problems/find-all-duplicates-in-an-array Medium
59 Array https://leetcode.com/problems/burst-balloons Hard
60 Array https://leetcode.com/problems/word-search-ii Hard
61 Array https://leetcode.com/problems/kth-smallest-element-in-a-sorted-matrix Medium
 62 Array https://leetcode.com/problems/4sum Medium
63 Array https://leetcode.com/problems/best-time-to-buy-and-sell-stock-iii Hard
64 Array https://leetcode.com/problems/best-time-to-buy-and-sell-stock-with-cooldown Medium
65 Array https://leetcode.com/problems/min-cost-climbing-stairs Easy
66 Array https://leetcode.com/problems/max-area-of-island Medium
67 Array https://leetcode.com/problems/count-of-smaller-numbers-after-self Hard
68 Array https://leetcode.com/problems/3sum-closest Medium
69 Array https://leetcode.com/problems/find-peak-element Medium
70 Array https://leetcode.com/problems/insert-delete-getrandom-o1 Medium
71 Array https://leetcode.com/problems/n-queens Hard
72 Array https://leetcode.com/problems/k-closest-points-to-origin Medium
73 Array https://leetcode.com/problems/shortest-unsorted-continuous-subarray Medium
74 Array https://leetcode.com/problems/queue-reconstruction-by-height Medium
75 Array https://leetcode.com/problems/missing-number Easy
76 Array https://leetcode.com/problems/evaluate-division Medium
77 Array https://leetcode.com/problems/house-robber-ii Medium
78 Array https://leetcode.com/problems/pascals-triangle Easy
79 Array https://leetcode.com/problems/coin-change-2 Medium
80 Array https://leetcode.com/problems/single-element-in-a-sorted-array Medium
81 Array https://leetcode.com/problems/gas-station Medium
82 Array https://leetcode.com/problems/sudoku-solver Hard
83 Array https://leetcode.com/problems/surrounded-regions Medium
84 Array https://leetcode.com/problems/partition-to-k-equal-sum-subsets Medium
85 Array https://leetcode.com/problems/two-sum-ii-input-array-is-sorted Easy
86 Array https://leetcode.com/problems/count-primes Medium
87 Array https://leetcode.com/problems/squares-of-a-sorted-array Easy
88 Array https://leetcode.com/problems/permutations-ii Medium
89 Array https://leetcode.com/problems/combination-sum-ii Medium
90 Array https://leetcode.com/problems/triangle Medium
91 Array https://leetcode.com/problems/valid-sudoku Medium
92 Array https://leetcode.com/problems/insert-interval Medium
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718 Array https://leetcode.com/problems/find-the-kth-largest-integer-in-the-array Medium
719 Array https://leetcode.com/problems/shortest-completing-word Easy
720 Array https://leetcode.com/problems/circular-array-loop Medium
721 Array https://leetcode.com/problems/maximum-ice-cream-bars Medium
722 Array https://leetcode.com/problems/reduction-operations-to-make-the-array-elements-equal
Medium
723 Array https://leetcode.com/problems/transform-to-chessboard Hard
724 Array https://leetcode.com/problems/moving-stones-until-consecutive-ii Medium
725 Array https://leetcode.com/problems/final-value-of-variable-after-performing-operationsEasy
726 Array https://leetcode.com/problems/minimum-area-rectangle-ii Medium
727 Array https://leetcode.com/problems/eliminate-maximum-number-of-monsters Medium
728 Array https://leetcode.com/problems/find-target-indices-after-sorting-array Easy
729 Array https://leetcode.com/problems/range-frequency-queries Medium
730 Array https://leetcode.com/problems/count-nodes-with-the-highest-score Medium
731 Array https://leetcode.com/problems/largest-values-from-labels Medium
732 Array https://leetcode.com/problems/find-the-distance-value-between-two-arrays Easy
733 Array https://leetcode.com/problems/sum-of-floored-pairs Hard
734 Array https://leetcode.com/problems/find-all-possible-recipes-from-given-supplies Medium
735 Array https://leetcode.com/problems/minimized-maximum-of-products-distributed-to-any-store
Medium
736 Array https://leetcode.com/problems/find-servers-that-handled-most-number-of-requests Hard
737 Array https://leetcode.com/problems/teemo-attacking Easy
738 Array https://leetcode.com/problems/find-xor-sum-of-all-pairs-bitwise-and Hard
739 Array https://leetcode.com/problems/find-the-middle-index-in-array Easy
740 Array https://leetcode.com/problems/plates-between-candles Medium
741 Array https://leetcode.com/problems/find-kth-largest-xor-coordinate-value Medium
742 Array https://leetcode.com/problems/invalid-transactions Medium
743 Array https://leetcode.com/problems/evaluate-the-bracket-pairs-of-a-string Medium
744 Array https://leetcode.com/problems/find-all-groups-of-farmland Medium
745 Array https://leetcode.com/problems/decrease-elements-to-make-array-zigzag Medium
746 Array https://leetcode.com/problems/find-a-value-of-a-mysterious-function-closest-to-target
Hard
747 Array https://leetcode.com/problems/finding-pairs-with-a-certain-sum Medium
748 Array https://leetcode.com/problems/merge-triplets-to-form-target-triplet Medium
749 Array https://leetcode.com/problems/describe-the-painting Medium
750 Array https://leetcode.com/problems/count-pairs-with-xor-in-a-range Hard
751 Array https://leetcode.com/problems/optimal-division Medium
752 Array https://leetcode.com/problems/find-greatest-common-divisor-of-array Easy
753 Array https://leetcode.com/problems/make-the-xor-of-all-segments-equal-to-zero Hard
754 Array https://leetcode.com/problems/stone-game-viii Hard
755 Array https://leetcode.com/problems/self-crossing Hard
756 Array https://leetcode.com/problems/longest-common-subpath Hard
757 Array https://leetcode.com/problems/remove-stones-to-minimize-the-total Medium
758 Array https://leetcode.com/problems/minimum-operations-to-make-a-uni-value-grid Medium
759 Array https://leetcode.com/problems/maximum-matrix-sum Medium
760 Array https://leetcode.com/problems/sum-of-beauty-in-the-array Medium
761 Array https://leetcode.com/problems/mean-of-array-after-removing-some-elements Easy
762 Array https://leetcode.com/problems/maximum-building-height Hard
763 Array https://leetcode.com/problems/magic-squares-in-grid Medium
764 Array https://leetcode.com/problems/most-beautiful-item-for-each-query Medium
765 Array https://leetcode.com/problems/number-of-different-subsequences-gcds Hard
766 Array https://leetcode.com/problems/watering-plants Medium
767 Array https://leetcode.com/problems/maximum-number-of-ways-to-partition-an-array Hard
768 Array https://leetcode.com/problems/two-furthest-houses-with-different-colors Easy
769 Array https://leetcode.com/problems/find-nearest-point-that-has-the-same-x-or-y-coordinate
Easy
770 Array https://leetcode.com/problems/number-of-smooth-descent-periods-of-a-stock Medium
771 Array https://leetcode.com/problems/people-whose-list-of-favorite-companies-is-not-a-subset-of-another-list
Medium
772 Array https://leetcode.com/problems/minimum-space-wasted-from-packaging Hard
773 Array https://leetcode.com/problems/maximum-difference-between-increasing-elements Easy
774 Array https://leetcode.com/problems/gcd-sort-of-an-array Hard
775 Array https://leetcode.com/problems/find-subsequence-of-length-k-with-the-largest-sum Easy
776 Array https://leetcode.com/problems/number-of-ways-where-square-of-number-is-equal-to-product-of-two-numbers
Medium
777 Array https://leetcode.com/problems/delivering-boxes-from-storage-to-ports Hard
778 Array https://leetcode.com/problems/array-with-elements-not-equal-to-average-of-neighbors
Medium
779 Array https://leetcode.com/problems/triples-with-bitwise-and-equal-to-zero Hard
780 Array https://leetcode.com/problems/number-of-ways-to-form-a-target-string-given-a-dictionary
Hard
781 Array https://leetcode.com/problems/check-if-all-the-integers-in-a-range-are-covered Easy
782 Array https://leetcode.com/problems/time-needed-to-buy-tickets Easy
783 Array https://leetcode.com/problems/check-if-it-is-a-good-array Hard
784 Array https://leetcode.com/problems/minimum-difference-between-highest-and-lowest-of-k-scores
Easy
785 Array https://leetcode.com/problems/maximum-fruits-harvested-after-at-most-k-steps Hard
786 Array https://leetcode.com/problems/contain-virus Hard
787 Array https://leetcode.com/problems/adding-two-negabinary-numbers Medium
788 Array https://leetcode.com/problems/maximum-number-of-groups-getting-fresh-donutsHard
789 Array https://leetcode.com/problems/maximum-genetic-difference-query Hard
790 Array https://leetcode.com/problems/removing-minimum-and-maximum-from-array Medium
791 Array https://leetcode.com/problems/find-good-days-to-rob-the-bank Medium
792 Array https://leetcode.com/problems/get-watched-videos-by-your-friends Medium
793 Array https://leetcode.com/problems/filter-restaurants-by-vegan-friendly-price-and-distance
Medium
794 Array https://leetcode.com/problems/detonate-the-maximum-bombs Medium
795 Array https://leetcode.com/problems/sentence-similarity-iii Medium
796 Array https://leetcode.com/problems/two-out-of-three Easy
797 Array https://leetcode.com/problems/the-time-when-the-network-becomes-idle Medium
798 Array https://leetcode.com/problems/kth-smallest-product-of-two-sorted-arrays Hard
799 Array https://leetcode.com/problems/minimum-cost-homecoming-of-a-robot-in-a-grid Medium
800 Array https://leetcode.com/problems/find-the-student-that-will-replace-the-chalk Medium
801 Array https://leetcode.com/problems/distribute-repeating-integers Hard
802 Array https://leetcode.com/problems/minimum-number-of-operations-to-reinitialize-a-permutation
Medium
803 Array https://leetcode.com/problems/add-minimum-number-of-rungs Medium
804 Array https://leetcode.com/problems/minimum-moves-to-reach-target-with-rotations Hard
805 Array https://leetcode.com/problems/count-special-quadruplets Easy
806 Array https://leetcode.com/problems/number-of-pairs-of-interchangeable-rectangles Medium
807 Array https://leetcode.com/problems/number-of-pairs-of-strings-with-concatenation-equal-to-target
Medium
808 Array https://leetcode.com/problems/four-divisors Medium
809 Array https://leetcode.com/problems/most-visited-sector-in-a-circular-track Easy
810 Array https://leetcode.com/problems/form-array-by-concatenating-subarrays-of-another-array
Medium
811 Array https://leetcode.com/problems/minimum-skips-to-arrive-at-meeting-on-time Hard
812 Array https://leetcode.com/problems/find-missing-observations Medium
813 Array https://leetcode.com/problems/maximum-path-quality-of-a-graph Hard
814 Array https://leetcode.com/problems/display-table-of-food-orders-in-a-restaurant Medium
815 Array https://leetcode.com/problems/detect-squares Medium
816 Array https://leetcode.com/problems/the-number-of-good-subsets Hard
817 Array https://leetcode.com/problems/k-radius-subarray-averages Medium
818 Array https://leetcode.com/problems/kth-distinct-string-in-an-array Easy
819 Array https://leetcode.com/problems/design-an-ordered-stream Easy
820 Array https://leetcode.com/problems/largest-magic-square Medium
821 Array https://leetcode.com/problems/convert-1d-array-into-2d-array Easy
822 Array https://leetcode.com/problems/minimum-number-of-moves-to-seat-everyone Easy
823 Array https://leetcode.com/problems/check-if-string-is-a-prefix-of-array Easy
824 Array https://leetcode.com/problems/previous-permutation-with-one-swap Medium
825 Array https://leetcode.com/problems/maximum-number-of-tasks-you-can-assign Hard
826 Array https://leetcode.com/problems/maximum-candies-you-can-get-from-boxes Hard
827 Array https://leetcode.com/problems/count-number-of-maximum-bitwise-or-subsets Medium
828 Array https://leetcode.com/problems/minimum-incompatibility Hard
829 Array https://leetcode.com/problems/maximum-element-after-decreasing-and-rearranging Medium
830 Array https://leetcode.com/problems/find-array-given-subset-sums Hard
831 Array https://leetcode.com/problems/adding-spaces-to-a-string Medium
832 Array https://leetcode.com/problems/count-common-words-with-one-occurrence Easy
833 Array https://leetcode.com/problems/recover-the-original-array Hard
834 Array https://leetcode.com/problems/minimum-distance-to-the-target-element Easy
835 Array https://leetcode.com/problems/count-unhappy-friends Medium
836 Array https://leetcode.com/problems/find-first-palindromic-string-in-the-array Easy
837 Array https://leetcode.com/problems/number-of-orders-in-the-backlog Medium
838 Array https://leetcode.com/problems/cyclically-rotating-a-grid Medium
839 Array https://leetcode.com/problems/alert-using-same-key-card-three-or-more-times-in-a-one-hour-period
Medium
840 Array https://leetcode.com/problems/delete-duplicate-folders-in-system Hard
841 Array https://leetcode.com/problems/widest-vertical-area-between-two-points-containing-no-points
Medium
842 Array https://leetcode.com/problems/count-ways-to-make-array-with-product Hard
843 Array https://leetcode.com/problems/finding-3-digit-even-numbers Easy
844 Array https://leetcode.com/problems/maximum-number-of-words-found-in-sentences Easy
845 Array https://leetcode.com/problems/minimum-elements-to-add-to-form-a-given-sum Medium
846 Array https://leetcode.com/problems/count-fertile-pyramids-in-a-land Hard
847 Array https://leetcode.com/problems/design-movie-rental-system Hard
848 Array https://leetcode.com/problems/largest-number-after-mutating-substring Medium
849 Array https://leetcode.com/problems/minimum-number-of-people-to-teach Medium
850 Array https://leetcode.com/problems/get-biggest-three-rhombus-sums-in-a-grid Medium
851 Array https://leetcode.com/problems/stone-game-ix Medium
852 Array https://leetcode.com/problems/check-if-word-can-be-placed-in-crossword Medium
853 Array https://leetcode.com/problems/the-score-of-students-solving-math-expression Hard
854 Array https://leetcode.com/problems/chalkboard-xor-game Hard
855 Array https://leetcode.com/problems/maximum-number-of-darts-inside-of-a-circular-dartboard
Hard
856 Array https://leetcode.com/problems/apply-discount-every-n-orders Medium
857 Array https://leetcode.com/problems/card-flipping-game Medium
858 Array https://leetcode.com/problems/smallest-index-with-equal-value Easy
859 Array https://leetcode.com/problems/simple-bank-system Medium
860 Array https://leetcode.com/problems/watering-plants-ii Medium
861 Array https://leetcode.com/problems/can-you-eat-your-favorite-candy-on-your-favorite-day
Medium
862 Array https://leetcode.com/problems/check-if-move-is-legal Medium
863 Array https://leetcode.com/problems/image-overlap Medium
864 Array https://leetcode.com/problems/maximum-profit-of-operating-a-centennial-wheel Medium
865 Array https://leetcode.com/problems/coordinate-with-maximum-network-quality Medium
866 Array https://leetcode.com/problems/escape-the-ghosts Medium
867 Array https://leetcode.com/problems/walking-robot-simulation Medium
868 Array https://leetcode.com/problems/number-of-valid-move-combinations-on-chessboard Hard
 Crack The Coding Interview - Dinesh Varyani
https://www.youtube.com/user/hubberspot?sub_confirmation=1

# Topic Question Difficulty

1 String https://leetcode.com/problems/longest-substring-without-repeating-characters Medium

2 String https://leetcode.com/problems/longest-palindromic-substring Medium
3 String https://leetcode.com/problems/generate-parentheses Medium
4 String https://leetcode.com/problems/valid-parentheses Easy
5 String https://leetcode.com/problems/word-break Medium
6 String https://leetcode.com/problems/minimum-window-substring Hard
7 String https://leetcode.com/problems/letter-combinations-of-a-phone-number Medium
8 String https://leetcode.com/problems/group-anagrams Medium
9 String https://leetcode.com/problems/edit-distance Hard
10 String https://leetcode.com/problems/regular-expression-matching Hard
11 String https://leetcode.com/problems/decode-string Medium
12 String https://leetcode.com/problems/longest-valid-parentheses Hard
13 String https://leetcode.com/problems/word-ladder Hard
14 String https://leetcode.com/problems/longest-common-prefix Easy
15 String https://leetcode.com/problems/implement-trie-prefix-tree Medium
16 String https://leetcode.com/problems/partition-labels Medium
17 String https://leetcode.com/problems/decode-ways Medium
18 String https://leetcode.com/problems/serialize-and-deserialize-binary-tree Hard
19 String https://leetcode.com/problems/find-all-anagrams-in-a-string Medium
20 String https://leetcode.com/problems/palindromic-substrings Medium
21 String https://leetcode.com/problems/word-search-ii Hard
22 String https://leetcode.com/problems/longest-common-subsequence Medium
23 String https://leetcode.com/problems/palindrome-partitioning Medium
24 String https://leetcode.com/problems/longest-palindromic-subsequence Medium
25 String https://leetcode.com/problems/remove-k-digits Medium
26 String https://leetcode.com/problems/remove-invalid-parentheses Hard
27 String https://leetcode.com/problems/first-unique-character-in-a-string Easy
28 String https://leetcode.com/problems/largest-number Medium
29 String https://leetcode.com/problems/word-break-ii Hard
30 String https://leetcode.com/problems/wildcard-matching Hard
31 String https://leetcode.com/problems/reorganize-string Medium
32 String https://leetcode.com/problems/permutation-in-string Medium
33 String https://leetcode.com/problems/top-k-frequent-words Medium
34 String https://leetcode.com/problems/add-binary Easy
35 String https://leetcode.com/problems/valid-anagram Easy
36 String https://leetcode.com/problems/multiply-strings Medium
37 String https://leetcode.com/problems/design-add-and-search-words-data-structure Medium
38 String https://leetcode.com/problems/basic-calculator-ii Medium
39 String https://leetcode.com/problems/accounts-merge Medium
40 String https://leetcode.com/problems/valid-palindrome-ii Easy
41 String https://leetcode.com/problems/remove-duplicate-letters Medium
42 String https://leetcode.com/problems/reverse-string Easy
43 String https://leetcode.com/problems/sort-characters-by-frequency Medium
44 String https://leetcode.com/problems/longest-repeating-character-replacement Medium
45 String https://leetcode.com/problems/is-subsequence Easy
46 String https://leetcode.com/problems/binary-tree-paths Easy
47 String https://leetcode.com/problems/longest-substring-with-at-least-k-repeating-characters
Medium
48 String https://leetcode.com/problems/interleaving-string Medium
49 String https://leetcode.com/problems/backspace-string-compare Easy
50 String https://leetcode.com/problems/implement-strstr Easy
51 String https://leetcode.com/problems/word-ladder-ii Hard
52 String https://leetcode.com/problems/minimum-remove-to-make-valid-parentheses Medium
53 String https://leetcode.com/problems/basic-calculator Hard
54 String https://leetcode.com/problems/jewels-and-stones Easy
55 String https://leetcode.com/problems/zigzag-conversion Medium
56 String https://leetcode.com/problems/different-ways-to-add-parentheses Medium
57 String https://leetcode.com/problems/isomorphic-strings Easy
58 String https://leetcode.com/problems/valid-parenthesis-string Medium
59 String https://leetcode.com/problems/repeated-substring-pattern Easy
60 String https://leetcode.com/problems/distinct-subsequences Hard
61 String https://leetcode.com/problems/palindrome-partitioning-ii Hard
 62 String https://leetcode.com/problems/score-of-parentheses Medium
63 String https://leetcode.com/problems/longest-string-chain Medium
64 String https://leetcode.com/problems/valid-palindrome Easy
65 String https://leetcode.com/problems/letter-case-permutation Medium
66 String https://leetcode.com/problems/add-strings Easy
67 String https://leetcode.com/problems/roman-to-integer Easy
68 String https://leetcode.com/problems/remove-all-adjacent-duplicates-in-string Easy
69 String https://leetcode.com/problems/reverse-words-in-a-string Medium
70 String https://leetcode.com/problems/integer-to-roman Medium
71 String https://leetcode.com/problems/word-pattern Easy
72 String https://leetcode.com/problems/ones-and-zeroes Medium
73 String https://leetcode.com/problems/number-of-matching-subsequences Medium
74 String https://leetcode.com/problems/open-the-lock Medium
75 String https://leetcode.com/problems/serialize-and-deserialize-bst Medium
76 String https://leetcode.com/problems/palindrome-pairs Hard
77 String https://leetcode.com/problems/verifying-an-alien-dictionary Easy
78 String https://leetcode.com/problems/delete-operation-for-two-strings Medium
79 String https://leetcode.com/problems/count-binary-substrings Easy
80 String https://leetcode.com/problems/restore-ip-addresses Medium
81 String https://leetcode.com/problems/expression-add-operators Hard
82 String https://leetcode.com/problems/excel-sheet-column-title Easy
83 String https://leetcode.com/problems/remove-all-adjacent-duplicates-in-string-ii Medium
84 String https://leetcode.com/problems/longest-palindrome Easy
85 String https://leetcode.com/problems/reverse-words-in-a-string-iii Easy
86 String https://leetcode.com/problems/excel-sheet-column-number Easy
87 String https://leetcode.com/problems/shortest-palindrome Hard
88 String https://leetcode.com/problems/robot-bounded-in-circle Medium
89 String https://leetcode.com/problems/find-common-characters Easy
90 String https://leetcode.com/problems/shortest-distance-to-a-character Easy
91 String https://leetcode.com/problems/minimum-add-to-make-parentheses-valid Medium
92 String https://leetcode.com/problems/integer-to-english-words Hard
93 String https://leetcode.com/problems/next-greater-element-iii Medium
94 String https://leetcode.com/problems/search-suggestions-system Medium
95 String https://leetcode.com/problems/time-based-key-value-store Medium
96 String https://leetcode.com/problems/string-compression Medium
97 String https://leetcode.com/problems/shortest-common-supersequence Hard
98 String https://leetcode.com/problems/find-the-difference Easy
99 String https://leetcode.com/problems/minimum-ascii-delete-sum-for-two-strings Medium
100 String https://leetcode.com/problems/custom-sort-string Medium
101 String https://leetcode.com/problems/concatenated-words Hard
102 String https://leetcode.com/problems/repeated-dna-sequences Medium
103 String https://leetcode.com/problems/substring-with-concatenation-of-all-words Hard
104 String https://leetcode.com/problems/find-and-replace-pattern Medium
105 String https://leetcode.com/problems/rotate-string Easy
106 String https://leetcode.com/problems/unique-email-addresses Easy
107 String https://leetcode.com/problems/maximum-product-of-word-lengths Medium
108 String https://leetcode.com/problems/flip-string-to-monotone-increasing Medium
109 String https://leetcode.com/problems/maximum-length-of-a-concatenated-string-with-unique-characters
Medium
110 String https://leetcode.com/problems/verify-preorder-serialization-of-a-binary-tree Medium
111 String https://leetcode.com/problems/robot-return-to-origin Easy
112 String https://leetcode.com/problems/longest-duplicate-substring Hard
113 String https://leetcode.com/problems/split-a-string-in-balanced-strings Easy
114 String https://leetcode.com/problems/di-string-match Easy
115 String https://leetcode.com/problems/push-dominoes Medium
116 String https://leetcode.com/problems/text-justification Hard
117 String https://leetcode.com/problems/reorder-data-in-log-files Easy
118 String https://leetcode.com/problems/letter-tile-possibilities Medium
119 String https://leetcode.com/problems/fraction-to-recurring-decimal Medium
120 String https://leetcode.com/problems/stream-of-characters Hard
121 String https://leetcode.com/problems/long-pressed-name Easy
122 String https://leetcode.com/problems/ransom-note Easy
123 String https://leetcode.com/problems/reverse-vowels-of-a-string Easy
124 String https://leetcode.com/problems/minimum-insertion-steps-to-make-a-string-palindrome
Hard
125 String https://leetcode.com/problems/smallest-subsequence-of-distinct-characters Medium
126 String https://leetcode.com/problems/replace-words Medium
127 String https://leetcode.com/problems/reverse-only-letters Easy
128 String https://leetcode.com/problems/buddy-strings Easy
129 String https://leetcode.com/problems/repeated-string-match Medium
130 String https://leetcode.com/problems/satisfiability-of-equality-equations Medium
131 String https://leetcode.com/problems/smallest-string-with-swaps Medium
132 String https://leetcode.com/problems/longest-word-in-dictionary-through-deleting Medium
133 String https://leetcode.com/problems/construct-string-from-binary-tree Easy
134 String https://leetcode.com/problems/scramble-string Hard
135 String https://leetcode.com/problems/bulls-and-cows Medium
136 String https://leetcode.com/problems/longest-word-in-dictionary Medium
137 String https://leetcode.com/problems/number-of-substrings-containing-all-three-characters
Medium
138 String https://leetcode.com/problems/most-common-word Easy
139 String https://leetcode.com/problems/count-different-palindromic-subsequences Hard
140 String https://leetcode.com/problems/consecutive-characters Easy
141 String https://leetcode.com/problems/simplify-path Medium
142 String https://leetcode.com/problems/guess-the-word Hard
143 String https://leetcode.com/problems/unique-morse-code-words Easy
144 String https://leetcode.com/problems/number-of-good-ways-to-split-a-string Medium
145 String https://leetcode.com/problems/remove-outermost-parentheses Easy
146 String https://leetcode.com/problems/greatest-common-divisor-of-strings Easy
147 String https://leetcode.com/problems/map-sum-pairs Medium
148 String https://leetcode.com/problems/reverse-substrings-between-each-pair-of-parentheses
Medium
149 String https://leetcode.com/problems/decoded-string-at-index Medium
150 String https://leetcode.com/problems/minimum-number-of-operations-to-move-all-balls-to-each-box
Medium
151 String https://leetcode.com/problems/shuffle-string Easy
152 String https://leetcode.com/problems/encode-and-decode-tinyurl Medium
153 String https://leetcode.com/problems/iterator-for-combination Medium
154 String https://leetcode.com/problems/count-and-say Medium
155 String https://leetcode.com/problems/design-underground-system Medium
156 String https://leetcode.com/problems/minimum-index-sum-of-two-lists Easy
157 String https://leetcode.com/problems/compare-version-numbers Medium
158 String https://leetcode.com/problems/number-of-valid-words-for-each-puzzle Hard
159 String https://leetcode.com/problems/unique-substrings-in-wraparound-string Medium
160 String https://leetcode.com/problems/minimum-deletions-to-make-character-frequencies-unique
Medium
161 String https://leetcode.com/problems/minimum-number-of-steps-to-make-two-strings-anagram
Medium
162 String https://leetcode.com/problems/detect-capital Easy
163 String https://leetcode.com/problems/find-the-longest-substring-containing-vowels-in-even-counts
Medium
164 String https://leetcode.com/problems/decode-ways-ii Hard
165 String https://leetcode.com/problems/distinct-subsequences-ii Hard
166 String https://leetcode.com/problems/subdomain-visit-count Medium
167 String https://leetcode.com/problems/defanging-an-ip-address Easy
168 String https://leetcode.com/problems/count-unique-characters-of-all-substrings-of-a-given-string
Hard
169 String https://leetcode.com/problems/find-the-shortest-superstring Hard
170 String https://leetcode.com/problems/smallest-string-starting-from-leaf Medium
171 String https://leetcode.com/problems/string-to-integer-atoi Medium
172 String https://leetcode.com/problems/recover-a-tree-from-preorder-traversal Hard
173 String https://leetcode.com/problems/prefix-and-suffix-search Hard
174 String https://leetcode.com/problems/implement-magic-dictionary Medium
175 String https://leetcode.com/problems/to-lower-case Easy
176 String https://leetcode.com/problems/maximum-number-of-balloons Easy
177 String https://leetcode.com/problems/longest-absolute-file-path Medium
178 String https://leetcode.com/problems/word-subsets Medium
179 String https://leetcode.com/problems/longest-happy-string Medium
180 String https://leetcode.com/problems/find-words-that-can-be-formed-by-characters Easy
181 String https://leetcode.com/problems/number-of-atoms Hard
182 String https://leetcode.com/problems/destination-city Easy
183 String https://leetcode.com/problems/minimum-time-difference Medium
184 String https://leetcode.com/problems/uncommon-words-from-two-sentences Easy
185 String https://leetcode.com/problems/minimum-time-to-make-rope-colorful Medium
186 String https://leetcode.com/problems/keyboard-row Easy
187 String https://leetcode.com/problems/reverse-string-ii Easy
188 String https://leetcode.com/problems/shifting-letters Medium
189 String https://leetcode.com/problems/split-array-into-fibonacci-sequence Medium
190 String https://leetcode.com/problems/find-duplicate-file-in-system Medium
191 String https://leetcode.com/problems/decrypt-string-from-alphabet-to-integer-mapping Easy
192 String https://leetcode.com/problems/minimum-swaps-to-make-strings-equal Medium
193 String https://leetcode.com/problems/k-similar-strings Hard
194 String https://leetcode.com/problems/strange-printer Hard
195 String https://leetcode.com/problems/minimum-genetic-mutation Medium
196 String https://leetcode.com/problems/license-key-formatting Easy
197 String https://leetcode.com/problems/minimum-distance-to-type-a-word-using-two-fingers Hard
198 String https://leetcode.com/problems/similar-string-groups Hard
199 String https://leetcode.com/problems/swap-adjacent-in-lr-string Medium
200 String https://leetcode.com/problems/rank-teams-by-votes Medium
201 String https://leetcode.com/problems/replace-the-substring-for-balanced-string Medium
202 String https://leetcode.com/problems/additive-number Medium
203 String https://leetcode.com/problems/jump-game-vii Medium
204 String https://leetcode.com/problems/short-encoding-of-words Medium
205 String https://leetcode.com/problems/break-a-palindrome Medium
206 String https://leetcode.com/problems/maximum-nesting-depth-of-the-parentheses Easy
207 String https://leetcode.com/problems/sorting-the-sentence Easy
208 String https://leetcode.com/problems/find-and-replace-in-string Medium
209 String https://leetcode.com/problems/partitioning-into-minimum-number-of-deci-binary-numbers
Medium
210 String https://leetcode.com/problems/count-the-number-of-consistent-strings Easy
211 String https://leetcode.com/problems/swap-for-longest-repeated-character-substring Medium
212 String https://leetcode.com/problems/check-if-a-string-contains-all-binary-codes-of-size-k
Medium
213 String https://leetcode.com/problems/freedom-trail Hard
214 String https://leetcode.com/problems/goat-latin Easy
215 String https://leetcode.com/problems/count-items-matching-a-rule Easy
216 String https://leetcode.com/problems/expressive-words Medium
217 String https://leetcode.com/problems/make-the-string-great Easy
218 String https://leetcode.com/problems/validate-ip-address Medium
219 String https://leetcode.com/problems/palindrome-partitioning-iii Hard
220 String https://leetcode.com/problems/check-if-two-string-arrays-are-equivalent Easy
221 String https://leetcode.com/problems/maximum-number-of-vowels-in-a-substring-of-given-length
Medium
222 String https://leetcode.com/problems/construct-k-palindrome-strings Medium
223 String https://leetcode.com/problems/the-k-th-lexicographical-string-of-all-happy-strings-of-length-n
Medium
224 String https://leetcode.com/problems/alphabet-board-path Medium
225 String https://leetcode.com/problems/determine-if-two-strings-are-close Medium
226 String https://leetcode.com/problems/positions-of-large-groups Easy
227 String https://leetcode.com/problems/minimum-number-of-frogs-croaking Medium
228 String https://leetcode.com/problems/minimum-suffix-flips Medium
229 String https://leetcode.com/problems/get-equal-substrings-within-budget Medium
230 String https://leetcode.com/problems/longest-happy-prefix Hard
231 String https://leetcode.com/problems/minimum-deletions-to-make-string-balanced Medium
232 String https://leetcode.com/problems/minimum-insertions-to-balance-a-parentheses-string Medium
233 String https://leetcode.com/problems/longest-uncommon-subsequence-i Easy
234 String https://leetcode.com/problems/number-of-wonderful-substrings Medium
235 String https://leetcode.com/problems/parsing-a-boolean-expression Hard
236 String https://leetcode.com/problems/remove-comments Medium
237 String https://leetcode.com/problems/maximum-score-words-formed-by-letters Hard
238 String https://leetcode.com/problems/check-if-the-sentence-is-pangram Easy
239 String https://leetcode.com/problems/orderly-queue Hard
240 String https://leetcode.com/problems/remove-sub-folders-from-the-filesystem Medium
241 String https://leetcode.com/problems/goal-parser-interpretation Easy
242 String https://leetcode.com/problems/minimum-number-of-flips-to-make-the-binary-string-alternating
Medium
243 String https://leetcode.com/problems/smallest-string-with-a-given-numeric-value Medium
244 String https://leetcode.com/problems/count-substrings-that-differ-by-one-character Medium
245 String https://leetcode.com/problems/maximum-number-of-occurrences-of-a-substring Medium
246 String https://leetcode.com/problems/largest-time-for-given-digits Medium
247 String https://leetcode.com/problems/stamping-the-sequence Hard
248 String https://leetcode.com/problems/reconstruct-original-digits-from-english Medium
249 String https://leetcode.com/problems/special-binary-string Hard
250 String https://leetcode.com/problems/check-if-word-is-valid-after-substitutions Medium
251 String https://leetcode.com/problems/can-make-palindrome-from-substring Medium
252 String https://leetcode.com/problems/camelcase-matching Medium
253 String https://leetcode.com/problems/minimum-number-of-swaps-to-make-the-string-balancedMedium
254 String https://leetcode.com/problems/split-a-string-into-the-max-number-of-unique-substrings
Medium
255 String https://leetcode.com/problems/maximum-number-of-removable-characters Medium
256 String https://leetcode.com/problems/slowest-key Easy
257 String https://leetcode.com/problems/complex-number-multiplication Medium
258 String https://leetcode.com/problems/increasing-decreasing-string Easy
259 String https://leetcode.com/problems/find-longest-awesome-substring Hard
260 String https://leetcode.com/problems/compare-strings-by-frequency-of-the-smallest-character
Medium
261 String https://leetcode.com/problems/number-of-substrings-with-only-1s Medium
262 String https://leetcode.com/problems/length-of-last-word Easy
263 String https://leetcode.com/problems/string-matching-in-an-array Easy
264 String https://leetcode.com/problems/check-if-a-string-can-break-another-string Medium
265 String https://leetcode.com/problems/maximum-score-after-splitting-a-string Easy
266 String https://leetcode.com/problems/find-the-closest-palindrome Hard
267 String https://leetcode.com/problems/split-two-strings-to-make-palindrome Medium
268 String https://leetcode.com/problems/check-if-a-word-occurs-as-a-prefix-of-any-word-in-a-sentence
Easy
269 String https://leetcode.com/problems/path-crossing Easy
270 String https://leetcode.com/problems/strong-password-checker Hard
271 String https://leetcode.com/problems/string-without-aaa-or-bbb Medium
272 String https://leetcode.com/problems/rearrange-words-in-a-sentence Medium
273 String https://leetcode.com/problems/determine-if-string-halves-are-alike Easy
274 String https://leetcode.com/problems/maximum-number-of-non-overlapping-substringsHard
275 String https://leetcode.com/problems/delete-columns-to-make-sorted-ii Medium
276 String https://leetcode.com/problems/number-of-steps-to-reduce-a-number-in-binary-representation-to-one
Medium
277 String https://leetcode.com/problems/last-substring-in-lexicographical-order Hard
278 String https://leetcode.com/problems/longest-nice-substring Easy
279 String https://leetcode.com/problems/remove-all-occurrences-of-a-substring Medium
280 String https://leetcode.com/problems/string-compression-ii Hard
281 String https://leetcode.com/problems/groups-of-special-equivalent-strings Medium
282 String https://leetcode.com/problems/palindrome-partitioning-iv Hard
283 String https://leetcode.com/problems/dota2-senate Medium
284 String https://leetcode.com/problems/delete-columns-to-make-sorted-iii Hard
285 String https://leetcode.com/problems/number-of-segments-in-a-string Easy
286 String https://leetcode.com/problems/valid-number Hard
287 String https://leetcode.com/problems/substrings-of-size-three-with-distinct-characters Easy
288 String https://leetcode.com/problems/crawler-log-folder Easy
289 String https://leetcode.com/problems/longest-chunked-palindrome-decomposition Hard
290 String https://leetcode.com/problems/find-kth-bit-in-nth-binary-string Medium
291 String https://leetcode.com/problems/merge-strings-alternately Easy
292 String https://leetcode.com/problems/number-of-ways-to-split-a-string Medium
293 String https://leetcode.com/problems/print-words-vertically Medium
294 String https://leetcode.com/problems/parse-lisp-expression Hard
295 String https://leetcode.com/problems/truncate-sentence Easy
296 String https://leetcode.com/problems/unique-length-3-palindromic-subsequences Medium
297 String https://leetcode.com/problems/find-unique-binary-string Medium
298 String https://leetcode.com/problems/valid-tic-tac-toe-state Medium
299 String https://leetcode.com/problems/minimum-changes-to-make-alternating-binary-string Easy
300 String https://leetcode.com/problems/reformat-the-string Easy
301 String https://leetcode.com/problems/replace-all-s-to-avoid-consecutive-repeating-characters
Easy
302 String https://leetcode.com/problems/number-of-lines-to-write-string Easy
303 String https://leetcode.com/problems/longest-uncommon-subsequence-ii Medium
304 String https://leetcode.com/problems/mini-parser Medium
305 String https://leetcode.com/problems/solve-the-equation Medium
306 String https://leetcode.com/problems/step-by-step-directions-from-a-binary-tree-node-to-another
Medium
307 String https://leetcode.com/problems/brace-expansion-ii Hard
308 String https://leetcode.com/problems/minimum-adjacent-swaps-to-reach-the-kth-smallest-number
Medium
309 String https://leetcode.com/problems/maximum-score-from-removing-substrings Medium
310 String https://leetcode.com/problems/longest-substring-of-all-vowels-in-order Medium
311 String https://leetcode.com/problems/count-number-of-homogenous-substrings Medium
312 String https://leetcode.com/problems/determine-color-of-a-chessboard-square Easy
313 String https://leetcode.com/problems/vowel-spellchecker Medium
314 String https://leetcode.com/problems/largest-substring-between-two-equal-characters Easy
315 String https://leetcode.com/problems/maximum-repeating-substring Easy
316 String https://leetcode.com/problems/zuma-game Hard
317 String https://leetcode.com/problems/maximum-product-of-the-length-of-two-palindromic-subsequences
Medium
318 String https://leetcode.com/problems/delete-columns-to-make-sorted Easy
319 String https://leetcode.com/problems/restore-the-array Hard
320 String https://leetcode.com/problems/check-if-string-is-transformable-with-substring-sort-operations
Hard
321 String https://leetcode.com/problems/replace-all-digits-with-characters Easy
322 String https://leetcode.com/problems/maximize-palindrome-length-from-subsequences Hard
323 String https://leetcode.com/problems/check-if-one-string-swap-can-make-strings-equal Easy
324 String https://leetcode.com/problems/occurrences-after-bigram Easy
325 String https://leetcode.com/problems/number-of-unique-good-subsequences Hard
326 String https://leetcode.com/problems/making-file-names-unique Medium
327 String https://leetcode.com/problems/largest-merge-of-two-strings Medium
328 String https://leetcode.com/problems/maximize-the-confusion-of-an-exam Medium
329 String https://leetcode.com/problems/thousand-separator Easy
330 String https://leetcode.com/problems/largest-odd-number-in-string Easy
331 String https://leetcode.com/problems/check-if-word-equals-summation-of-two-words Easy
332 String https://leetcode.com/problems/fraction-addition-and-subtraction Medium
333 String https://leetcode.com/problems/verbal-arithmetic-puzzle Hard
334 String https://leetcode.com/problems/minimum-possible-integer-after-at-most-k-adjacent-swaps-on-digits
Hard
335 String https://leetcode.com/problems/find-the-kth-largest-integer-in-the-array Medium
336 String https://leetcode.com/problems/shortest-completing-word Easy
337 String https://leetcode.com/problems/count-the-repetitions Hard
338 String https://leetcode.com/problems/maximum-binary-string-after-change Medium
339 String https://leetcode.com/problems/final-value-of-variable-after-performing-operationsEasy
340 String https://leetcode.com/problems/generate-a-string-with-characters-that-have-odd-counts
Easy
341 String https://leetcode.com/problems/number-of-different-integers-in-a-string Easy
342 String https://leetcode.com/problems/sum-of-beauty-of-all-substrings Medium
343 String https://leetcode.com/problems/splitting-a-string-into-descending-consecutive-values
Medium
344 String https://leetcode.com/problems/can-convert-string-in-k-moves Medium
345 String https://leetcode.com/problems/find-all-possible-recipes-from-given-supplies Medium
346 String https://leetcode.com/problems/maximum-nesting-depth-of-two-valid-parentheses-strings
Medium
347 String https://leetcode.com/problems/plates-between-candles Medium
348 String https://leetcode.com/problems/invalid-transactions Medium
349 String https://leetcode.com/problems/minimum-time-to-type-word-using-special-typewriter Easy
350 String https://leetcode.com/problems/evaluate-the-bracket-pairs-of-a-string Medium
351 String https://leetcode.com/problems/find-all-good-strings Hard
352 String https://leetcode.com/problems/minimum-number-of-swaps-to-make-the-binary-string-alternating
Medium
353 String https://leetcode.com/problems/vowels-of-all-substrings Medium
354 String https://leetcode.com/problems/ambiguous-coordinates Medium
355 String https://leetcode.com/problems/count-vowel-substrings-of-a-string Easy
356 String https://leetcode.com/problems/longer-contiguous-segments-of-ones-than-zeros Easy
357 String https://leetcode.com/problems/check-if-all-characters-have-equal-number-of-occurrences
Easy
358 String https://leetcode.com/problems/minimum-length-of-string-after-deleting-similar-ends
Medium
359 String https://leetcode.com/problems/rearrange-spaces-between-words Easy
360 String https://leetcode.com/problems/student-attendance-record-i Easy
361 String https://leetcode.com/problems/binary-string-with-substrings-representing-1-to-n Medium
362 String https://leetcode.com/problems/redistribute-characters-to-make-all-strings-equal Easy
363 String https://leetcode.com/problems/people-whose-list-of-favorite-companies-is-not-a-subset-of-another-list
Medium
364 String https://leetcode.com/problems/minimum-number-of-buckets-required-to-collect-rainwater-from-houses
Medium
365 String https://leetcode.com/problems/day-of-the-year Easy
366 String https://leetcode.com/problems/maximum-number-of-words-you-can-type Easy
367 String https://leetcode.com/problems/number-of-ways-to-form-a-target-string-given-a-dictionary
Hard
368 String https://leetcode.com/problems/check-if-a-parentheses-string-can-be-valid Medium
369 String https://leetcode.com/problems/reverse-prefix-of-word Easy
370 String https://leetcode.com/problems/lexicographically-smallest-string-after-applying-operations
Medium
371 String https://leetcode.com/problems/reformat-date Easy
372 String https://leetcode.com/problems/second-largest-digit-in-a-string Easy
373 String https://leetcode.com/problems/change-minimum-characters-to-satisfy-one-of-three-conditions
Medium
374 String https://leetcode.com/problems/maximum-value-after-insertion Medium
375 String https://leetcode.com/problems/sentence-similarity-iii Medium
376 String https://leetcode.com/problems/number-of-strings-that-appear-as-substrings-in-wordEasy
377 String https://leetcode.com/problems/latest-time-by-replacing-hidden-digits Easy
378 String https://leetcode.com/problems/sum-of-digits-of-string-after-convert Easy
379 String https://leetcode.com/problems/reformat-phone-number Easy
380 String https://leetcode.com/problems/number-of-pairs-of-strings-with-concatenation-equal-to-target
Medium
381 String https://leetcode.com/problems/display-table-of-food-orders-in-a-restaurant Medium
382 String https://leetcode.com/problems/number-of-ways-to-separate-numbers Hard
383 String https://leetcode.com/problems/smallest-k-length-subsequence-with-occurrences-of-a-letter
Hard
384 String https://leetcode.com/problems/kth-distinct-string-in-an-array Easy
385 String https://leetcode.com/problems/delete-characters-to-make-fancy-string Easy
386 String https://leetcode.com/problems/magical-string Medium
387 String https://leetcode.com/problems/check-if-string-is-a-prefix-of-array Easy
388 String https://leetcode.com/problems/rings-and-rods Easy
389 String https://leetcode.com/problems/number-of-days-between-two-dates Easy
390 String https://leetcode.com/problems/adding-spaces-to-a-string Medium
391 String https://leetcode.com/problems/count-common-words-with-one-occurrence Easy
392 String https://leetcode.com/problems/remove-palindromic-subsequences Easy
393 String https://leetcode.com/problems/distinct-echo-substrings Hard
394 String https://leetcode.com/problems/remove-colored-pieces-if-both-neighbors-are-the-same-color
Medium
395 String https://leetcode.com/problems/check-if-numbers-are-ascending-in-a-sentence Easy
396 String https://leetcode.com/problems/minimum-moves-to-convert-string Easy
397 String https://leetcode.com/problems/find-first-palindromic-string-in-the-array Easy
398 String https://leetcode.com/problems/execution-of-all-suffix-instructions-staying-in-a-grid
Medium
399 String https://leetcode.com/problems/check-if-binary-string-has-at-most-one-segment-of-ones
Easy
400 String https://leetcode.com/problems/alert-using-same-key-card-three-or-more-times-in-a-one-hour-period
Medium
401 String https://leetcode.com/problems/delete-duplicate-folders-in-system Hard
402 String https://leetcode.com/problems/longest-subsequence-repeated-k-times Hard
403 String https://leetcode.com/problems/the-number-of-full-rounds-you-have-played Medium
404 String https://leetcode.com/problems/minimum-cost-to-change-the-final-value-of-expression
Hard
405 String https://leetcode.com/problems/maximum-number-of-words-found-in-sentences Easy
406 String https://leetcode.com/problems/html-entity-parser Medium
407 String https://leetcode.com/problems/check-whether-two-strings-are-almost-equivalent Easy
408 String https://leetcode.com/problems/tag-validator Hard
409 String https://leetcode.com/problems/largest-number-after-mutating-substring Medium
410 String https://leetcode.com/problems/decode-the-slanted-ciphertext Medium
411 String https://leetcode.com/problems/the-score-of-students-solving-math-expression Hard
412 String https://leetcode.com/problems/minimum-number-of-operations-to-make-string-sorted Hard
413 String https://leetcode.com/problems/masking-personal-information Medium
414 String https://leetcode.com/problems/basic-calculator-iv Hard
415 String https://leetcode.com/problems/check-if-an-original-string-exists-given-two-encoded-strings
Hard
416 String https://leetcode.com/problems/maximum-product-of-the-length-of-two-palindromic-substrings
Hard
417 String https://leetcode.com/problems/fizz-buzz Easy
418 String https://leetcode.com/problems/number-of-valid-words-in-a-sentence Easy
419 String https://leetcode.com/problems/equal-rational-numbers Hard
420 String https://leetcode.com/problems/number-of-valid-move-combinations-on-chessboard Hard
 Crack The Coding Interview - Dinesh Varyani
https://www.youtube.com/user/hubberspot?sub_confirmation=1

# Topic Question Difficulty

1 Dynamic Programming https://leetcode.com/problems/maximum-subarray Easy

2 Dynamic Programming https://leetcode.com/problems/trapping-rain-water Hard
3 Dynamic Programming https://leetcode.com/problems/longest-palindromic-substring Medium
4 Dynamic Programming https://leetcode.com/problems/best-time-to-buy-and-sell-stock Easy
5 Dynamic Programming https://leetcode.com/problems/generate-parentheses Medium
6 Dynamic Programming https://leetcode.com/problems/house-robber Medium
7 Dynamic Programming https://leetcode.com/problems/longest-increasing-subsequence Medium
8 Dynamic Programming https://leetcode.com/problems/maximum-product-subarray Medium
9 Dynamic Programming https://leetcode.com/problems/climbing-stairs Easy
10 Dynamic Programming https://leetcode.com/problems/coin-change Medium
11 Dynamic Programming https://leetcode.com/problems/jump-game Medium
12 Dynamic Programming https://leetcode.com/problems/word-break Medium
13 Dynamic Programming https://leetcode.com/problems/binary-tree-maximum-path-sum Hard
14 Dynamic Programming https://leetcode.com/problems/unique-paths Medium
15 Dynamic Programming https://leetcode.com/problems/edit-distance Hard
16 Dynamic Programming https://leetcode.com/problems/regular-expression-matching Hard
17 Dynamic Programming https://leetcode.com/problems/longest-valid-parentheses Hard
18 Dynamic Programming https://leetcode.com/problems/jump-game-ii Medium
19 Dynamic Programming https://leetcode.com/problems/partition-equal-subset-sum Medium
20 Dynamic Programming https://leetcode.com/problems/unique-binary-search-trees Medium
21 Dynamic Programming https://leetcode.com/problems/maximal-square Medium
22 Dynamic Programming https://leetcode.com/problems/best-time-to-buy-and-sell-stock-ii Medium
23 Dynamic Programming https://leetcode.com/problems/minimum-path-sum Medium
24 Dynamic Programming https://leetcode.com/problems/perfect-squares Medium
25 Dynamic Programming https://leetcode.com/problems/decode-ways Medium
26 Dynamic Programming https://leetcode.com/problems/maximal-rectangle Hard
27 Dynamic Programming https://leetcode.com/problems/target-sum Medium
28 Dynamic Programming https://leetcode.com/problems/house-robber-iii Medium
29 Dynamic Programming https://leetcode.com/problems/palindromic-substrings Medium
30 Dynamic Programming https://leetcode.com/problems/burst-balloons Hard
31 Dynamic Programming https://leetcode.com/problems/counting-bits Easy
32 Dynamic Programming https://leetcode.com/problems/longest-common-subsequence Medium
33 Dynamic Programming https://leetcode.com/problems/best-time-to-buy-and-sell-stock-iii Hard
34 Dynamic Programming https://leetcode.com/problems/best-time-to-buy-and-sell-stock-with-cooldown Medium
35 Dynamic Programming https://leetcode.com/problems/palindrome-partitioning Medium
36 Dynamic Programming https://leetcode.com/problems/min-cost-climbing-stairs Easy
37 Dynamic Programming https://leetcode.com/problems/longest-increasing-path-in-a-matrix Hard
38 Dynamic Programming https://leetcode.com/problems/longest-palindromic-subsequence Medium
39 Dynamic Programming https://leetcode.com/problems/house-robber-ii Medium
40 Dynamic Programming https://leetcode.com/problems/pascals-triangle Easy
41 Dynamic Programming https://leetcode.com/problems/coin-change-2 Medium
42 Dynamic Programming https://leetcode.com/problems/unique-binary-search-trees-ii Medium
43 Dynamic Programming https://leetcode.com/problems/cheapest-flights-within-k-stops Medium
44 Dynamic Programming https://leetcode.com/problems/partition-to-k-equal-sum-subsets Medium
45 Dynamic Programming https://leetcode.com/problems/word-break-ii Hard
46 Dynamic Programming https://leetcode.com/problems/triangle Medium
47 Dynamic Programming https://leetcode.com/problems/wildcard-matching Hard
48 Dynamic Programming https://leetcode.com/problems/unique-paths-ii Medium
49 Dynamic Programming https://leetcode.com/problems/split-array-largest-sum Hard
50 Dynamic Programming https://leetcode.com/problems/minimum-cost-for-tickets Medium
51 Dynamic Programming https://leetcode.com/problems/01-matrix Medium
52 Dynamic Programming https://leetcode.com/problems/dungeon-game Hard
53 Dynamic Programming https://leetcode.com/problems/ugly-number-ii Medium
54 Dynamic Programming https://leetcode.com/problems/is-subsequence Easy
55 Dynamic Programming https://leetcode.com/problems/best-time-to-buy-and-sell-stock-with-transaction-fee
Medium
56 Dynamic Programming https://leetcode.com/problems/interleaving-string Medium
57 Dynamic Programming https://leetcode.com/problems/best-time-to-buy-and-sell-stock-iv Hard
58 Dynamic Programming https://leetcode.com/problems/maximum-length-of-repeated-subarray Medium
59 Dynamic Programming https://leetcode.com/problems/non-overlapping-intervals Medium
60 Dynamic Programming https://leetcode.com/problems/different-ways-to-add-parentheses Medium
61 Dynamic Programming https://leetcode.com/problems/number-of-longest-increasing-subsequence Medium
 62 Dynamic Programming https://leetcode.com/problems/valid-parenthesis-string Medium
63 Dynamic Programming https://leetcode.com/problems/combination-sum-iv Medium
64 Dynamic Programming https://leetcode.com/problems/distinct-subsequences Hard
65 Dynamic Programming https://leetcode.com/problems/largest-divisible-subset Medium
66 Dynamic Programming https://leetcode.com/problems/delete-and-earn Medium
67 Dynamic Programming https://leetcode.com/problems/sum-of-subarray-minimums Medium
68 Dynamic Programming https://leetcode.com/problems/count-square-submatrices-with-all-ones Medium
69 Dynamic Programming https://leetcode.com/problems/palindrome-partitioning-ii Hard
70 Dynamic Programming https://leetcode.com/problems/longest-string-chain Medium
71 Dynamic Programming https://leetcode.com/problems/minimum-cost-tree-from-leaf-values Medium
72 Dynamic Programming https://leetcode.com/problems/russian-doll-envelopes Hard
73 Dynamic Programming https://leetcode.com/problems/maximum-profit-in-job-scheduling Hard
74 Dynamic Programming https://leetcode.com/problems/predict-the-winner Medium
75 Dynamic Programming https://leetcode.com/problems/maximum-sum-circular-subarray Medium
76 Dynamic Programming https://leetcode.com/problems/fibonacci-number Easy
77 Dynamic Programming https://leetcode.com/problems/arithmetic-slices Medium
78 Dynamic Programming https://leetcode.com/problems/ones-and-zeroes Medium
79 Dynamic Programming https://leetcode.com/problems/delete-operation-for-two-strings Medium
80 Dynamic Programming https://leetcode.com/problems/integer-break Medium
81 Dynamic Programming https://leetcode.com/problems/binary-tree-cameras Hard
82 Dynamic Programming https://leetcode.com/problems/wiggle-subsequence Medium
83 Dynamic Programming https://leetcode.com/problems/sum-of-distances-in-tree Hard
84 Dynamic Programming https://leetcode.com/problems/2-keys-keyboard Medium
85 Dynamic Programming https://leetcode.com/problems/minimum-number-of-refueling-stops Hard
86 Dynamic Programming https://leetcode.com/problems/all-possible-full-binary-trees Medium
87 Dynamic Programming https://leetcode.com/problems/cherry-pickup Hard
88 Dynamic Programming https://leetcode.com/problems/frog-jump Hard
89 Dynamic Programming https://leetcode.com/problems/pascals-triangle-ii Easy
90 Dynamic Programming https://leetcode.com/problems/super-egg-drop Hard
91 Dynamic Programming https://leetcode.com/problems/maximum-length-of-pair-chain Medium
92 Dynamic Programming https://leetcode.com/problems/minimum-swaps-to-make-sequences-increasing Hard
93 Dynamic Programming https://leetcode.com/problems/partition-array-for-maximum-sum Medium
94 Dynamic Programming https://leetcode.com/problems/longest-arithmetic-subsequence Medium
95 Dynamic Programming https://leetcode.com/problems/last-stone-weight-ii Medium
96 Dynamic Programming https://leetcode.com/problems/beautiful-arrangement Medium
97 Dynamic Programming https://leetcode.com/problems/minimum-falling-path-sum Medium
98 Dynamic Programming https://leetcode.com/problems/max-sum-of-rectangle-no-larger-than-k Hard
99 Dynamic Programming https://leetcode.com/problems/shortest-common-supersequence Hard
100 Dynamic Programming https://leetcode.com/problems/number-of-dice-rolls-with-target-sum Medium
101 Dynamic Programming https://leetcode.com/problems/stone-game Medium
102 Dynamic Programming https://leetcode.com/problems/knight-probability-in-chessboard Medium
103 Dynamic Programming https://leetcode.com/problems/minimum-ascii-delete-sum-for-two-strings Medium
104 Dynamic Programming https://leetcode.com/problems/can-i-win Medium
105 Dynamic Programming https://leetcode.com/problems/concatenated-words Hard
106 Dynamic Programming https://leetcode.com/problems/count-number-of-teams Medium
107 Dynamic Programming https://leetcode.com/problems/longest-mountain-in-array Medium
108 Dynamic Programming https://leetcode.com/problems/flip-string-to-monotone-increasing Medium
109 Dynamic Programming https://leetcode.com/problems/count-sorted-vowel-strings Medium
110 Dynamic Programming https://leetcode.com/problems/push-dominoes Medium
111 Dynamic Programming https://leetcode.com/problems/maximum-sum-of-3-non-overlapping-subarrays Hard
112 Dynamic Programming https://leetcode.com/problems/uncrossed-lines Medium
113 Dynamic Programming https://leetcode.com/problems/maximum-sum-of-two-non-overlapping-subarraysMedium
114 Dynamic Programming https://leetcode.com/problems/largest-sum-of-averages Medium
115 Dynamic Programming https://leetcode.com/problems/matchsticks-to-square Medium
116 Dynamic Programming https://leetcode.com/problems/remove-boxes Hard
117 Dynamic Programming https://leetcode.com/problems/minimum-cost-to-merge-stones Hard
118 Dynamic Programming https://leetcode.com/problems/out-of-boundary-paths Medium
119 Dynamic Programming https://leetcode.com/problems/minimum-insertion-steps-to-make-a-string-palindrome
Hard
120 Dynamic Programming https://leetcode.com/problems/n-th-tribonacci-number Easy
121 Dynamic Programming https://leetcode.com/problems/count-submatrices-with-all-ones Medium
122 Dynamic Programming https://leetcode.com/problems/guess-number-higher-or-lower-ii Medium
123 Dynamic Programming https://leetcode.com/problems/as-far-from-land-as-possible Medium
124 Dynamic Programming https://leetcode.com/problems/domino-and-tromino-tiling Medium
125 Dynamic Programming https://leetcode.com/problems/length-of-longest-fibonacci-subsequence Medium
126 Dynamic Programming https://leetcode.com/problems/super-ugly-number Medium
127 Dynamic Programming https://leetcode.com/problems/minimum-number-of-taps-to-open-to-water-a-garden
Hard
128 Dynamic Programming https://leetcode.com/problems/shortest-path-visiting-all-nodes Hard
129 Dynamic Programming https://leetcode.com/problems/knight-dialer Medium
130 Dynamic Programming https://leetcode.com/problems/best-sightseeing-pair Medium
131 Dynamic Programming https://leetcode.com/problems/scramble-string Hard
132 Dynamic Programming https://leetcode.com/problems/odd-even-jump Hard
133 Dynamic Programming https://leetcode.com/problems/arithmetic-slices-ii-subsequence Hard
134 Dynamic Programming https://leetcode.com/problems/longest-turbulent-subarray Medium
135 Dynamic Programming https://leetcode.com/problems/count-different-palindromic-subsequences Hard
136 Dynamic Programming https://leetcode.com/problems/stone-game-ii Medium
137 Dynamic Programming https://leetcode.com/problems/filling-bookcase-shelves Medium
138 Dynamic Programming https://leetcode.com/problems/divisor-game Easy
139 Dynamic Programming https://leetcode.com/problems/number-of-good-ways-to-split-a-string Medium
140 Dynamic Programming https://leetcode.com/problems/jump-game-vi Medium
141 Dynamic Programming https://leetcode.com/problems/maximum-subarray-sum-with-one-deletion Medium
142 Dynamic Programming https://leetcode.com/problems/video-stitching Medium
143 Dynamic Programming https://leetcode.com/problems/find-two-non-overlapping-sub-arrays-each-with-target-sum
Medium
144 Dynamic Programming https://leetcode.com/problems/greatest-sum-divisible-by-three Medium
145 Dynamic Programming https://leetcode.com/problems/cherry-pickup-ii Hard
146 Dynamic Programming https://leetcode.com/problems/largest-plus-sign Medium
147 Dynamic Programming https://leetcode.com/problems/minimum-difficulty-of-a-job-schedule Hard
148 Dynamic Programming https://leetcode.com/problems/numbers-at-most-n-given-digit-set Hard
149 Dynamic Programming https://leetcode.com/problems/non-negative-integers-without-consecutive-ones Hard
150 Dynamic Programming https://leetcode.com/problems/student-attendance-record-ii Hard
151 Dynamic Programming https://leetcode.com/problems/maximum-number-of-points-with-cost Medium
152 Dynamic Programming https://leetcode.com/problems/unique-substrings-in-wraparound-string Medium
153 Dynamic Programming https://leetcode.com/problems/decode-ways-ii Hard
154 Dynamic Programming https://leetcode.com/problems/champagne-tower Medium
155 Dynamic Programming https://leetcode.com/problems/maximum-length-of-subarray-with-positive-product Medium
156 Dynamic Programming https://leetcode.com/problems/distinct-subsequences-ii Hard
157 Dynamic Programming https://leetcode.com/problems/find-the-city-with-the-smallest-number-of-neighbors-at-a-threshold-distance
Medium
158 Dynamic Programming https://leetcode.com/problems/count-unique-characters-of-all-substrings-of-a-given-string
Hard
159 Dynamic Programming https://leetcode.com/problems/find-the-shortest-superstring Hard
160 Dynamic Programming https://leetcode.com/problems/minimum-cost-to-cut-a-stick Hard
161 Dynamic Programming https://leetcode.com/problems/shopping-offers Medium
162 Dynamic Programming https://leetcode.com/problems/minimum-score-triangulation-of-polygon Medium
163 Dynamic Programming https://leetcode.com/problems/longest-zigzag-path-in-a-binary-tree Medium
164 Dynamic Programming https://leetcode.com/problems/bitwise-ors-of-subarrays Medium
165 Dynamic Programming https://leetcode.com/problems/new-21-game Medium
166 Dynamic Programming https://leetcode.com/problems/count-vowels-permutation Hard
167 Dynamic Programming https://leetcode.com/problems/maximum-sum-bst-in-binary-tree Hard
168 Dynamic Programming https://leetcode.com/problems/stone-game-iii Hard
169 Dynamic Programming https://leetcode.com/problems/kth-ancestor-of-a-tree-node Hard
170 Dynamic Programming https://leetcode.com/problems/minimum-time-to-make-rope-colorful Medium
171 Dynamic Programming https://leetcode.com/problems/longest-arithmetic-subsequence-of-given-difference
Medium
172 Dynamic Programming https://leetcode.com/problems/binary-trees-with-factors Medium
173 Dynamic Programming https://leetcode.com/problems/count-numbers-with-unique-digits Medium
174 Dynamic Programming https://leetcode.com/problems/race-car Hard
175 Dynamic Programming https://leetcode.com/problems/k-concatenation-maximum-sum Medium
176 Dynamic Programming https://leetcode.com/problems/reducing-dishes Hard
177 Dynamic Programming https://leetcode.com/problems/split-array-with-same-average Hard
178 Dynamic Programming https://leetcode.com/problems/strange-printer Hard
179 Dynamic Programming https://leetcode.com/problems/minimum-number-of-increments-on-subarrays-to-form-a-target-array
Hard
180 Dynamic Programming https://leetcode.com/problems/k-inverse-pairs-array Hard
181 Dynamic Programming https://leetcode.com/problems/sort-integers-by-the-power-value Medium
182 Dynamic Programming https://leetcode.com/problems/rotate-function Medium
183 Dynamic Programming https://leetcode.com/problems/integer-replacement Medium
184 Dynamic Programming https://leetcode.com/problems/longest-subarray-of-1s-after-deleting-one-elementMedium
185 Dynamic Programming https://leetcode.com/problems/minimum-distance-to-type-a-word-using-two-fingersHard
186 Dynamic Programming https://leetcode.com/problems/number-of-ways-to-paint-n-3-grid Hard
187 Dynamic Programming https://leetcode.com/problems/ways-to-make-a-fair-array Medium
188 Dynamic Programming https://leetcode.com/problems/best-team-with-no-conflicts Medium
189 Dynamic Programming https://leetcode.com/problems/constrained-subsequence-sum Hard
190 Dynamic Programming https://leetcode.com/problems/stickers-to-spell-word Hard
191 Dynamic Programming https://leetcode.com/problems/number-of-music-playlists Hard
192 Dynamic Programming https://leetcode.com/problems/number-of-sub-arrays-with-odd-sum Medium
193 Dynamic Programming https://leetcode.com/problems/smallest-sufficient-team Hard
194 Dynamic Programming https://leetcode.com/problems/freedom-trail Hard
195 Dynamic Programming https://leetcode.com/problems/dice-roll-simulation Hard
196 Dynamic Programming https://leetcode.com/problems/palindrome-partitioning-iii Hard
197 Dynamic Programming https://leetcode.com/problems/where-will-the-ball-fall Medium
198 Dynamic Programming https://leetcode.com/problems/minimum-falling-path-sum-ii Hard
199 Dynamic Programming https://leetcode.com/problems/allocate-mailboxes Hard
200 Dynamic Programming https://leetcode.com/problems/poor-pigs Hard
201 Dynamic Programming https://leetcode.com/problems/number-of-squareful-arrays Hard
202 Dynamic Programming https://leetcode.com/problems/number-of-ways-to-arrive-at-destination Medium
203 Dynamic Programming https://leetcode.com/problems/number-of-digit-one Hard
204 Dynamic Programming https://leetcode.com/problems/stone-game-vii Medium
205 Dynamic Programming https://leetcode.com/problems/tallest-billboard Hard
206 Dynamic Programming https://leetcode.com/problems/minimum-jumps-to-reach-home Medium
207 Dynamic Programming https://leetcode.com/problems/minimum-number-of-days-to-eat-n-oranges Hard
208 Dynamic Programming https://leetcode.com/problems/maximum-absolute-sum-of-any-subarray Medium
209 Dynamic Programming https://leetcode.com/problems/cat-and-mouse Hard
210 Dynamic Programming https://leetcode.com/problems/jump-game-v Hard
211 Dynamic Programming https://leetcode.com/problems/minimum-number-of-removals-to-make-mountain-array Hard
212 Dynamic Programming https://leetcode.com/problems/make-array-strictly-increasing Hard
213 Dynamic Programming https://leetcode.com/problems/minimum-deletions-to-make-string-balanced Medium
214 Dynamic Programming https://leetcode.com/problems/rotated-digits Medium
215 Dynamic Programming https://leetcode.com/problems/egg-drop-with-2-eggs-and-n-floors Medium
216 Dynamic Programming https://leetcode.com/problems/maximum-score-words-formed-by-letters Hard
217 Dynamic Programming https://leetcode.com/problems/stone-game-iv Hard
218 Dynamic Programming https://leetcode.com/problems/number-of-ways-to-wear-different-hats-to-each-otherHard
219 Dynamic Programming https://leetcode.com/problems/max-dot-product-of-two-subsequences Hard
220 Dynamic Programming https://leetcode.com/problems/parallel-courses-ii Hard
221 Dynamic Programming https://leetcode.com/problems/count-substrings-that-differ-by-one-character Medium
222 Dynamic Programming https://leetcode.com/problems/maximum-students-taking-exam Hard
223 Dynamic Programming https://leetcode.com/problems/maximum-score-from-performing-multiplication-operations
Medium
224 Dynamic Programming https://leetcode.com/problems/get-the-maximum-score Hard
225 Dynamic Programming https://leetcode.com/problems/maximum-alternating-subsequence-sum Medium
226 Dynamic Programming https://leetcode.com/problems/number-of-restricted-paths-from-first-to-last-nodeMedium
227 Dynamic Programming https://leetcode.com/problems/minimum-sideway-jumps Medium
228 Dynamic Programming https://leetcode.com/problems/pizza-with-3n-slices Hard
229 Dynamic Programming https://leetcode.com/problems/number-of-ways-to-stay-in-the-same-place-after-some-steps
Hard
230 Dynamic Programming https://leetcode.com/problems/paint-house-iii Hard
231 Dynamic Programming https://leetcode.com/problems/maximum-non-negative-product-in-a-matrix Medium
232 Dynamic Programming https://leetcode.com/problems/form-largest-integer-with-digits-that-add-up-to-target
Hard
233 Dynamic Programming https://leetcode.com/problems/count-all-valid-pickup-and-delivery-options Hard
234 Dynamic Programming https://leetcode.com/problems/largest-1-bordered-square Medium
235 Dynamic Programming https://leetcode.com/problems/valid-permutations-for-di-sequence Hard
236 Dynamic Programming https://leetcode.com/problems/find-minimum-time-to-finish-all-jobs Hard
237 Dynamic Programming https://leetcode.com/problems/tiling-a-rectangle-with-the-fewest-squares Hard
238 Dynamic Programming https://leetcode.com/problems/minimum-number-of-work-sessions-to-finish-the-tasksMedium
239 Dynamic Programming https://leetcode.com/problems/string-compression-ii Hard
240 Dynamic Programming https://leetcode.com/problems/number-of-ways-to-rearrange-sticks-with-k-sticks-visible
Hard
241 Dynamic Programming https://leetcode.com/problems/maximum-height-by-stacking-cuboids Hard
242 Dynamic Programming https://leetcode.com/problems/number-of-ways-of-cutting-a-pizza Hard
243 Dynamic Programming https://leetcode.com/problems/palindrome-partitioning-iv Hard
244 Dynamic Programming https://leetcode.com/problems/delete-columns-to-make-sorted-iii Hard
245 Dynamic Programming https://leetcode.com/problems/maximum-earnings-from-taxi Medium
246 Dynamic Programming https://leetcode.com/problems/profitable-schemes Hard
247 Dynamic Programming https://leetcode.com/problems/longest-chunked-palindrome-decomposition Hard
248 Dynamic Programming https://leetcode.com/problems/maximum-number-of-events-that-can-be-attended-ii Hard
249 Dynamic Programming https://leetcode.com/problems/build-array-where-you-can-find-the-maximum-exactly-k-comparisons
Hard
250 Dynamic Programming https://leetcode.com/problems/closest-subsequence-sum Hard
251 Dynamic Programming https://leetcode.com/problems/largest-color-value-in-a-directed-graph Hard
252 Dynamic Programming https://leetcode.com/problems/minimize-the-difference-between-target-and-chosen-elements
Medium
253 Dynamic Programming https://leetcode.com/problems/numbers-with-repeated-digits Hard
254 Dynamic Programming https://leetcode.com/problems/minimum-cost-to-reach-destination-in-time Hard
255 Dynamic Programming https://leetcode.com/problems/maximum-compatibility-score-sum Medium
256 Dynamic Programming https://leetcode.com/problems/number-of-ways-to-reorder-array-to-get-same-bstHard
257 Dynamic Programming https://leetcode.com/problems/largest-multiple-of-three Hard
258 Dynamic Programming https://leetcode.com/problems/minimum-xor-sum-of-two-arrays Hard
259 Dynamic Programming https://leetcode.com/problems/closest-dessert-cost Medium
260 Dynamic Programming https://leetcode.com/problems/minimum-total-space-wasted-with-k-resizing-operations
Medium
261 Dynamic Programming https://leetcode.com/problems/airplane-seat-assignment-probability Medium
262 Dynamic Programming https://leetcode.com/problems/zuma-game Hard
263 Dynamic Programming https://leetcode.com/problems/maximum-product-of-the-length-of-two-palindromic-subsequences
Medium
264 Dynamic Programming https://leetcode.com/problems/restore-the-array Hard
265 Dynamic Programming https://leetcode.com/problems/maximize-score-after-n-operations Hard
266 Dynamic Programming https://leetcode.com/problems/stone-game-v Hard
267 Dynamic Programming https://leetcode.com/problems/count-all-possible-routes Hard
268 Dynamic Programming https://leetcode.com/problems/count-number-of-special-subsequences Hard
269 Dynamic Programming https://leetcode.com/problems/maximize-palindrome-length-from-subsequences Hard
270 Dynamic Programming https://leetcode.com/problems/kth-smallest-instructions Hard
271 Dynamic Programming https://leetcode.com/problems/number-of-unique-good-subsequences Hard
272 Dynamic Programming https://leetcode.com/problems/minimum-cost-to-connect-two-groups-of-points Hard
273 Dynamic Programming https://leetcode.com/problems/get-maximum-in-generated-array Easy
274 Dynamic Programming https://leetcode.com/problems/partition-array-into-two-arrays-to-minimize-sum-difference
Hard
275 Dynamic Programming https://leetcode.com/problems/two-best-non-overlapping-events Medium
276 Dynamic Programming https://leetcode.com/problems/first-day-where-you-have-been-in-all-the-rooms Medium
277 Dynamic Programming https://leetcode.com/problems/number-of-paths-with-max-score Hard
278 Dynamic Programming https://leetcode.com/problems/number-of-sets-of-k-non-overlapping-line-segments Medium
279 Dynamic Programming https://leetcode.com/problems/count-the-repetitions Hard
280 Dynamic Programming https://leetcode.com/problems/painting-a-grid-with-three-different-colors Hard
281 Dynamic Programming https://leetcode.com/problems/minimum-one-bit-operations-to-make-integers-zero Hard
282 Dynamic Programming https://leetcode.com/problems/count-subtrees-with-max-distance-between-citiesHard
283 Dynamic Programming https://leetcode.com/problems/find-all-good-strings Hard
284 Dynamic Programming https://leetcode.com/problems/least-operators-to-express-number Hard
285 Dynamic Programming https://leetcode.com/problems/vowels-of-all-substrings Medium
286 Dynamic Programming https://leetcode.com/problems/optimal-division Medium
287 Dynamic Programming https://leetcode.com/problems/soup-servings Medium
288 Dynamic Programming https://leetcode.com/problems/make-the-xor-of-all-segments-equal-to-zero Hard
289 Dynamic Programming https://leetcode.com/problems/stone-game-viii Hard
290 Dynamic Programming https://leetcode.com/problems/parallel-courses-iii Hard
291 Dynamic Programming https://leetcode.com/problems/smallest-missing-genetic-value-in-each-subtree Hard
292 Dynamic Programming https://leetcode.com/problems/count-ways-to-build-rooms-in-an-ant-colony Hard
293 Dynamic Programming https://leetcode.com/problems/number-of-smooth-descent-periods-of-a-stock Medium
294 Dynamic Programming https://leetcode.com/problems/minimum-number-of-buckets-required-to-collect-rainwater-from-houses
Medium
295 Dynamic Programming https://leetcode.com/problems/delivering-boxes-from-storage-to-ports Hard
296 Dynamic Programming https://leetcode.com/problems/number-of-ways-to-form-a-target-string-given-a-dictionary
Hard
297 Dynamic Programming https://leetcode.com/problems/maximum-number-of-groups-getting-fresh-donutsHard
298 Dynamic Programming https://leetcode.com/problems/maximize-grid-happiness Hard
299 Dynamic Programming https://leetcode.com/problems/find-good-days-to-rob-the-bank Medium
300 Dynamic Programming https://leetcode.com/problems/probability-of-a-two-boxes-having-the-same-number-of-distinct-balls
Hard
301 Dynamic Programming https://leetcode.com/problems/distribute-repeating-integers Hard
302 Dynamic Programming https://leetcode.com/problems/minimum-skips-to-arrive-at-meeting-on-time Hard
303 Dynamic Programming https://leetcode.com/problems/number-of-ways-to-separate-numbers Hard
304 Dynamic Programming https://leetcode.com/problems/the-number-of-good-subsets Hard
305 Dynamic Programming https://leetcode.com/problems/minimum-incompatibility Hard
306 Dynamic Programming https://leetcode.com/problems/the-earliest-and-latest-rounds-where-players-compete
Hard
307 Dynamic Programming https://leetcode.com/problems/distinct-echo-substrings Hard
308 Dynamic Programming https://leetcode.com/problems/minimum-cost-to-change-the-final-value-of-expression
Hard
309 Dynamic Programming https://leetcode.com/problems/count-ways-to-make-array-with-product Hard
310 Dynamic Programming https://leetcode.com/problems/cat-and-mouse-ii Hard
311 Dynamic Programming https://leetcode.com/problems/count-fertile-pyramids-in-a-land Hard
312 Dynamic Programming https://leetcode.com/problems/the-score-of-students-solving-math-expression Hard
313 Dynamic Programming https://leetcode.com/problems/check-if-an-original-string-exists-given-two-encoded-strings
Hard
 Crack The Coding Interview - Dinesh Varyani
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# Topic Question Difficulty

1 Math https://leetcode.com/problems/add-two-numbers Medium

2 Math https://leetcode.com/problems/climbing-stairs Easy
3 Math https://leetcode.com/problems/unique-paths Medium
4 Math https://leetcode.com/problems/rotate-image Medium
5 Math https://leetcode.com/problems/rotate-array Medium
6 Math https://leetcode.com/problems/unique-binary-search-trees Medium
7 Math https://leetcode.com/problems/reverse-integer Medium
8 Math https://leetcode.com/problems/perfect-squares Medium
9 Math https://leetcode.com/problems/insert-delete-getrandom-o1 Medium
10 Math https://leetcode.com/problems/palindrome-number Easy
11 Math https://leetcode.com/problems/k-closest-points-to-origin Medium
12 Math https://leetcode.com/problems/missing-number Easy
13 Math https://leetcode.com/problems/happy-number Easy
14 Math https://leetcode.com/problems/count-primes Medium
15 Math https://leetcode.com/problems/add-binary Easy
16 Math https://leetcode.com/problems/multiply-strings Medium
17 Math https://leetcode.com/problems/basic-calculator-ii Medium
18 Math https://leetcode.com/problems/powx-n Medium
19 Math https://leetcode.com/problems/ugly-number-ii Medium
20 Math https://leetcode.com/problems/plus-one Easy
21 Math https://leetcode.com/problems/basic-calculator Hard
22 Math https://leetcode.com/problems/permutation-sequence Hard
23 Math https://leetcode.com/problems/different-ways-to-add-parentheses Medium
24 Math https://leetcode.com/problems/add-two-numbers-ii Medium
25 Math https://leetcode.com/problems/sqrtx Easy
26 Math https://leetcode.com/problems/largest-divisible-subset Medium
27 Math https://leetcode.com/problems/add-strings Easy
28 Math https://leetcode.com/problems/roman-to-integer Easy
29 Math https://leetcode.com/problems/integer-to-roman Medium
30 Math https://leetcode.com/problems/power-of-two Easy
31 Math https://leetcode.com/problems/predict-the-winner Medium
32 Math https://leetcode.com/problems/fibonacci-number Easy
33 Math https://leetcode.com/problems/evaluate-reverse-polish-notation Medium
34 Math https://leetcode.com/problems/divide-two-integers Medium
35 Math https://leetcode.com/problems/integer-break Medium
36 Math https://leetcode.com/problems/maximum-product-of-three-numbers Easy
37 Math https://leetcode.com/problems/expression-add-operators Hard
38 Math https://leetcode.com/problems/excel-sheet-column-title Easy
39 Math https://leetcode.com/problems/2-keys-keyboard Medium
40 Math https://leetcode.com/problems/excel-sheet-column-number Easy
41 Math https://leetcode.com/problems/sum-of-two-integers Medium
42 Math https://leetcode.com/problems/convert-binary-number-in-a-linked-list-to-integer Easy
43 Math https://leetcode.com/problems/maximum-swap Medium
44 Math https://leetcode.com/problems/super-egg-drop Hard
45 Math https://leetcode.com/problems/robot-bounded-in-circle Medium
46 Math https://leetcode.com/problems/number-of-good-pairs Easy
47 Math https://leetcode.com/problems/integer-to-english-words Hard
48 Math https://leetcode.com/problems/valid-perfect-square Easy
49 Math https://leetcode.com/problems/arranging-coins Easy
50 Math https://leetcode.com/problems/next-greater-element-iii Medium
51 Math https://leetcode.com/problems/factorial-trailing-zeroes Medium
52 Math https://leetcode.com/problems/stone-game Medium
53 Math https://leetcode.com/problems/can-i-win Medium
54 Math https://leetcode.com/problems/add-digits Easy
55 Math https://leetcode.com/problems/di-string-match Easy
56 Math https://leetcode.com/problems/sum-of-all-odd-length-subarrays Easy
57 Math https://leetcode.com/problems/total-hamming-distance Medium
58 Math https://leetcode.com/problems/insert-delete-getrandom-o1-duplicates-allowed Hard
59 Math https://leetcode.com/problems/fraction-to-recurring-decimal Medium
60 Math https://leetcode.com/problems/count-number-of-nice-subarrays Medium
61 Math https://leetcode.com/problems/k-th-symbol-in-grammar Medium
 62 Math https://leetcode.com/problems/number-of-steps-to-reduce-a-number-to-zero Easy
63 Math https://leetcode.com/problems/n-th-tribonacci-number Easy
64 Math https://leetcode.com/problems/guess-number-higher-or-lower-ii Medium
65 Math https://leetcode.com/problems/gray-code Medium
66 Math https://leetcode.com/problems/minimum-area-rectangle Medium
67 Math https://leetcode.com/problems/minimum-cost-to-move-chips-to-the-same-position Easy
68 Math https://leetcode.com/problems/rectangle-overlap Easy
69 Math https://leetcode.com/problems/super-ugly-number Medium
70 Math https://leetcode.com/problems/minimum-moves-to-equal-array-elements Medium
71 Math https://leetcode.com/problems/power-of-four Easy
72 Math https://leetcode.com/problems/continuous-subarray-sum Medium
73 Math https://leetcode.com/problems/minimum-moves-to-equal-array-elements-ii Medium
74 Math https://leetcode.com/problems/largest-component-size-by-common-factor Hard
75 Math https://leetcode.com/problems/sum-of-square-numbers Medium
76 Math https://leetcode.com/problems/prison-cells-after-n-days Medium
77 Math https://leetcode.com/problems/ugly-number Easy
78 Math https://leetcode.com/problems/stone-game-ii Medium
79 Math https://leetcode.com/problems/divisor-game Easy
80 Math https://leetcode.com/problems/guess-the-word Hard
81 Math https://leetcode.com/problems/24-game Hard
82 Math https://leetcode.com/problems/greatest-common-divisor-of-strings Easy
83 Math https://leetcode.com/problems/linked-list-random-node Medium
84 Math https://leetcode.com/problems/x-of-a-kind-in-a-deck-of-cards Easy
85 Math https://leetcode.com/problems/minimum-time-visiting-all-points Easy
86 Math https://leetcode.com/problems/global-and-local-inversions Medium
87 Math https://leetcode.com/problems/self-dividing-numbers Easy
88 Math https://leetcode.com/problems/broken-calculator Medium
89 Math https://leetcode.com/problems/numbers-at-most-n-given-digit-set Hard
90 Math https://leetcode.com/problems/smallest-range-ii Medium
91 Math https://leetcode.com/problems/reach-a-number Medium
92 Math https://leetcode.com/problems/nim-game Easy
93 Math https://leetcode.com/problems/add-to-array-form-of-integer Easy
94 Math https://leetcode.com/problems/smallest-integer-divisible-by-k Medium
95 Math https://leetcode.com/problems/nth-magical-number Hard
96 Math https://leetcode.com/problems/consecutive-numbers-sum Hard
97 Math https://leetcode.com/problems/new-21-game Medium
98 Math https://leetcode.com/problems/find-n-unique-integers-sum-up-to-zero Easy
99 Math https://leetcode.com/problems/reaching-points Hard
100 Math https://leetcode.com/problems/path-in-zigzag-labelled-binary-tree Medium
101 Math https://leetcode.com/problems/maximum-69-number Easy
102 Math https://leetcode.com/problems/stone-game-iii Hard
103 Math https://leetcode.com/problems/random-pick-index Medium
104 Math https://leetcode.com/problems/minimum-time-difference Medium
105 Math https://leetcode.com/problems/subtract-the-product-and-sum-of-digits-of-an-integer
Easy
106 Math https://leetcode.com/problems/implement-rand10-using-rand7 Medium
107 Math https://leetcode.com/problems/bulb-switcher Medium
108 Math https://leetcode.com/problems/angle-between-hands-of-a-clock Medium
109 Math https://leetcode.com/problems/convert-a-number-to-hexadecimal Easy
110 Math https://leetcode.com/problems/count-triplets-that-can-form-two-arrays-of-equal-xor
Medium
111 Math https://leetcode.com/problems/count-numbers-with-unique-digits Medium
112 Math https://leetcode.com/problems/monotone-increasing-digits Medium
113 Math https://leetcode.com/problems/product-of-the-last-k-numbers Medium
114 Math https://leetcode.com/problems/largest-perimeter-triangle Easy
115 Math https://leetcode.com/problems/beautiful-array Medium
116 Math https://leetcode.com/problems/find-the-winner-of-the-circular-game Medium
117 Math https://leetcode.com/problems/minimum-swaps-to-make-strings-equal Medium
118 Math https://leetcode.com/problems/split-array-with-same-average Hard
119 Math https://leetcode.com/problems/max-points-on-a-line Hard
120 Math https://leetcode.com/problems/rotate-function Medium
121 Math https://leetcode.com/problems/check-if-it-is-a-straight-line Easy
122 Math https://leetcode.com/problems/longest-subarray-of-1s-after-deleting-one-elementMedium
123 Math https://leetcode.com/problems/elimination-game Medium
124 Math https://leetcode.com/problems/rectangle-area Medium
125 Math https://leetcode.com/problems/minimum-operations-to-make-array-equal Medium
126 Math https://leetcode.com/problems/xor-operation-in-an-array Easy
127 Math https://leetcode.com/problems/three-equal-parts Hard
128 Math https://leetcode.com/problems/number-of-music-playlists Hard
129 Math https://leetcode.com/problems/distribute-candies-to-people Easy
130 Math https://leetcode.com/problems/number-of-sub-arrays-with-odd-sum Medium
131 Math https://leetcode.com/problems/power-of-three Easy
132 Math https://leetcode.com/problems/ugly-number-iii Medium
133 Math https://leetcode.com/problems/water-and-jug-problem Medium
134 Math https://leetcode.com/problems/cells-with-odd-values-in-a-matrix Easy
135 Math https://leetcode.com/problems/beautiful-arrangement-ii Medium
136 Math https://leetcode.com/problems/valid-square Medium
137 Math https://leetcode.com/problems/allocate-mailboxes Hard
138 Math https://leetcode.com/problems/water-bottles Easy
139 Math https://leetcode.com/problems/nth-digit Medium
140 Math https://leetcode.com/problems/poor-pigs Hard
141 Math https://leetcode.com/problems/number-of-squareful-arrays Hard
142 Math https://leetcode.com/problems/number-of-digit-one Hard
143 Math https://leetcode.com/problems/range-addition-ii Easy
144 Math https://leetcode.com/problems/stone-game-vii Medium
145 Math https://leetcode.com/problems/rabbits-in-forest Medium
146 Math https://leetcode.com/problems/shuffle-an-array Medium
147 Math https://leetcode.com/problems/sell-diminishing-valued-colored-balls Medium
148 Math https://leetcode.com/problems/sum-of-absolute-differences-in-a-sorted-array Medium
149 Math https://leetcode.com/problems/cat-and-mouse Hard
150 Math https://leetcode.com/problems/sum-of-all-subset-xor-totals Easy
151 Math https://leetcode.com/problems/random-pick-with-blacklist Hard
152 Math https://leetcode.com/problems/the-kth-factor-of-n Medium
153 Math https://leetcode.com/problems/rotated-digits Medium
154 Math https://leetcode.com/problems/number-of-boomerangs Medium
155 Math https://leetcode.com/problems/reordered-power-of-2 Medium
156 Math https://leetcode.com/problems/egg-drop-with-2-eggs-and-n-floors Medium
157 Math https://leetcode.com/problems/stone-game-iv Hard
158 Math https://leetcode.com/problems/erect-the-fence Hard
159 Math https://leetcode.com/problems/orderly-queue Hard
160 Math https://leetcode.com/problems/car-fleet-ii Hard
161 Math https://leetcode.com/problems/maximum-number-of-coins-you-can-get Medium
162 Math https://leetcode.com/problems/reconstruct-original-digits-from-english Medium
163 Math https://leetcode.com/problems/count-of-matches-in-tournament Easy
164 Math https://leetcode.com/problems/perfect-number Easy
165 Math https://leetcode.com/problems/complex-number-multiplication Medium
166 Math https://leetcode.com/problems/number-of-substrings-with-only-1s Medium
167 Math https://leetcode.com/problems/count-all-valid-pickup-and-delivery-options Hard
168 Math https://leetcode.com/problems/find-the-closest-palindrome Hard
169 Math https://leetcode.com/problems/check-if-number-is-a-sum-of-powers-of-three Medium
170 Math https://leetcode.com/problems/matrix-cells-in-distance-order Easy
171 Math https://leetcode.com/problems/sum-of-subsequence-widths Hard
172 Math https://leetcode.com/problems/base-7 Easy
173 Math https://leetcode.com/problems/maximum-of-absolute-value-expression Medium
174 Math https://leetcode.com/problems/prime-number-of-set-bits-in-binary-representationEasy
175 Math https://leetcode.com/problems/super-pow Medium
176 Math https://leetcode.com/problems/stone-game-vi Medium
177 Math https://leetcode.com/problems/number-of-ways-to-rearrange-sticks-with-k-sticks-visible
Hard
178 Math https://leetcode.com/problems/maximum-score-from-removing-stones Medium
179 Math https://leetcode.com/problems/queries-on-number-of-points-inside-a-circle Medium
180 Math https://leetcode.com/problems/binary-gap Easy
181 Math https://leetcode.com/problems/number-of-ways-to-split-a-string Medium
182 Math https://leetcode.com/problems/smallest-range-i Easy
183 Math https://leetcode.com/problems/calculate-money-in-leetcode-bank Easy
184 Math https://leetcode.com/problems/surface-area-of-3d-shapes Easy
185 Math https://leetcode.com/problems/random-point-in-non-overlapping-rectangles Medium
186 Math https://leetcode.com/problems/numbers-with-repeated-digits Hard
187 Math https://leetcode.com/problems/construct-the-rectangle Easy
188 Math https://leetcode.com/problems/projection-area-of-3d-shapes Easy
189 Math https://leetcode.com/problems/sign-of-the-product-of-an-array Easy
190 Math https://leetcode.com/problems/number-of-ways-to-reorder-array-to-get-same-bstHard
191 Math https://leetcode.com/problems/mirror-reflection Medium
192 Math https://leetcode.com/problems/count-nice-pairs-in-an-array Medium
193 Math https://leetcode.com/problems/solve-the-equation Medium
194 Math https://leetcode.com/problems/generate-random-point-in-a-circle Medium
195 Math https://leetcode.com/problems/count-number-of-homogenous-substrings Medium
196 Math https://leetcode.com/problems/determine-color-of-a-chessboard-square Easy
197 Math https://leetcode.com/problems/airplane-seat-assignment-probability Medium
198 Math https://leetcode.com/problems/maximize-score-after-n-operations Hard
199 Math https://leetcode.com/problems/maximum-number-of-balls-in-a-box Easy
200 Math https://leetcode.com/problems/find-positive-integer-solution-for-a-given-equationMedium
201 Math https://leetcode.com/problems/maximum-number-of-visible-points Hard
202 Math https://leetcode.com/problems/stone-game-v Hard
203 Math https://leetcode.com/problems/concatenation-of-consecutive-binary-numbers Medium
204 Math https://leetcode.com/problems/convert-to-base-2 Medium
205 Math https://leetcode.com/problems/reverse-subarray-to-maximize-array-value Hard
206 Math https://leetcode.com/problems/kth-smallest-instructions Hard
207 Math https://leetcode.com/problems/largest-triangle-area Easy
208 Math https://leetcode.com/problems/prime-palindrome Medium
209 Math https://leetcode.com/problems/super-palindromes Hard
210 Math https://leetcode.com/problems/largest-odd-number-in-string Easy
211 Math https://leetcode.com/problems/graph-connectivity-with-threshold Hard
212 Math https://leetcode.com/problems/random-pick-with-weight Medium
213 Math https://leetcode.com/problems/fraction-addition-and-subtraction Medium
214 Math https://leetcode.com/problems/verbal-arithmetic-puzzle Hard
215 Math https://leetcode.com/problems/number-of-sets-of-k-non-overlapping-line-segments Medium
216 Math https://leetcode.com/problems/count-odd-numbers-in-an-interval-range Easy
217 Math https://leetcode.com/problems/transform-to-chessboard Hard
218 Math https://leetcode.com/problems/moving-stones-until-consecutive-ii Medium
219 Math https://leetcode.com/problems/minimum-area-rectangle-ii Medium
220 Math https://leetcode.com/problems/random-flip-matrix Medium
221 Math https://leetcode.com/problems/preimage-size-of-factorial-zeroes-function Hard
222 Math https://leetcode.com/problems/sum-game Medium
223 Math https://leetcode.com/problems/sum-of-floored-pairs Hard
224 Math https://leetcode.com/problems/find-xor-sum-of-all-pairs-bitwise-and Hard
225 Math https://leetcode.com/problems/count-good-numbers Medium
226 Math https://leetcode.com/problems/smallest-good-base Hard
227 Math https://leetcode.com/problems/least-operators-to-express-number Hard
228 Math https://leetcode.com/problems/vowels-of-all-substrings Medium
229 Math https://leetcode.com/problems/optimal-division Medium
230 Math https://leetcode.com/problems/find-greatest-common-divisor-of-array Easy
231 Math https://leetcode.com/problems/sum-of-digits-in-base-k Easy
232 Math https://leetcode.com/problems/count-largest-group Easy
233 Math https://leetcode.com/problems/soup-servings Medium
234 Math https://leetcode.com/problems/convert-integer-to-the-sum-of-two-no-zero-integers Easy
235 Math https://leetcode.com/problems/stone-game-viii Hard
236 Math https://leetcode.com/problems/self-crossing Hard
237 Math https://leetcode.com/problems/minimum-operations-to-make-a-uni-value-grid Medium
238 Math https://leetcode.com/problems/maximum-building-height Hard
239 Math https://leetcode.com/problems/magic-squares-in-grid Medium
240 Math https://leetcode.com/problems/fancy-sequence Hard
241 Math https://leetcode.com/problems/number-of-different-subsequences-gcds Hard
242 Math https://leetcode.com/problems/prime-arrangements Easy
243 Math https://leetcode.com/problems/count-ways-to-build-rooms-in-an-ant-colony Hard
244 Math https://leetcode.com/problems/number-of-smooth-descent-periods-of-a-stock Medium
245 Math https://leetcode.com/problems/powerful-integers Medium
246 Math https://leetcode.com/problems/day-of-the-year Easy
247 Math https://leetcode.com/problems/circular-permutation-in-binary-representation Medium
248 Math https://leetcode.com/problems/gcd-sort-of-an-array Hard
249 Math https://leetcode.com/problems/number-of-ways-where-square-of-number-is-equal-to-product-of-two-numbers
Medium
250 Math https://leetcode.com/problems/circle-and-rectangle-overlapping Medium
251 Math https://leetcode.com/problems/day-of-the-week Easy
252 Math https://leetcode.com/problems/simplified-fractions Medium
253 Math https://leetcode.com/problems/valid-boomerang Easy
254 Math https://leetcode.com/problems/check-if-it-is-a-good-array Hard
255 Math https://leetcode.com/problems/tree-of-coprimes Hard
256 Math https://leetcode.com/problems/adding-two-negabinary-numbers Medium
257 Math https://leetcode.com/problems/number-of-burgers-with-no-waste-of-ingredients Medium
258 Math https://leetcode.com/problems/building-boxes Hard
259 Math https://leetcode.com/problems/detonate-the-maximum-bombs Medium
260 Math https://leetcode.com/problems/probability-of-a-two-boxes-having-the-same-number-of-distinct-balls
Hard
261 Math https://leetcode.com/problems/minimum-number-of-operations-to-reinitialize-a-permutation
Medium
262 Math https://leetcode.com/problems/number-of-pairs-of-interchangeable-rectangles Medium
263 Math https://leetcode.com/problems/four-divisors Medium
264 Math https://leetcode.com/problems/find-missing-observations Medium
265 Math https://leetcode.com/problems/three-divisors Easy
266 Math https://leetcode.com/problems/minimum-garden-perimeter-to-collect-enough-apples
Medium
267 Math https://leetcode.com/problems/the-number-of-good-subsets Hard
268 Math https://leetcode.com/problems/clumsy-factorial Medium
269 Math https://leetcode.com/problems/number-of-days-between-two-dates Easy
270 Math https://leetcode.com/problems/closest-divisors Medium
271 Math https://leetcode.com/problems/best-position-for-a-service-centre Hard
272 Math https://leetcode.com/problems/remove-colored-pieces-if-both-neighbors-are-the-same-color
Medium
273 Math https://leetcode.com/problems/moving-stones-until-consecutive Medium
274 Math https://leetcode.com/problems/the-number-of-full-rounds-you-have-played Medium
275 Math https://leetcode.com/problems/minimum-cost-to-change-the-final-value-of-expression
Hard
276 Math https://leetcode.com/problems/count-square-sum-triples Easy
277 Math https://leetcode.com/problems/count-ways-to-make-array-with-product Hard
278 Math https://leetcode.com/problems/cat-and-mouse-ii Hard
279 Math https://leetcode.com/problems/max-difference-you-can-get-from-changing-an-integer
Medium
280 Math https://leetcode.com/problems/maximize-number-of-nice-divisors Hard
281 Math https://leetcode.com/problems/get-biggest-three-rhombus-sums-in-a-grid Medium
282 Math https://leetcode.com/problems/stone-game-ix Medium
283 Math https://leetcode.com/problems/the-score-of-students-solving-math-expression Hard
284 Math https://leetcode.com/problems/a-number-after-a-double-reversal Easy
285 Math https://leetcode.com/problems/largest-palindrome-product Hard
286 Math https://leetcode.com/problems/chalkboard-xor-game Hard
287 Math https://leetcode.com/problems/minimum-number-of-operations-to-make-string-sorted
Hard
288 Math https://leetcode.com/problems/basic-calculator-iv Hard
289 Math https://leetcode.com/problems/maximum-number-of-darts-inside-of-a-circular-dartboard
Hard
290 Math https://leetcode.com/problems/minimum-non-zero-product-of-the-array-elementsMedium
291 Math https://leetcode.com/problems/fizz-buzz Easy
292 Math https://leetcode.com/problems/next-greater-numerically-balanced-number Medium
293 Math https://leetcode.com/problems/sum-of-k-mirror-numbers Hard
294 Math https://leetcode.com/problems/equal-rational-numbers Hard
295 Math https://leetcode.com/problems/escape-the-ghosts Medium
296 Math https://leetcode.com/problems/abbreviating-the-product-of-a-range Hard
297 Math https://leetcode.com/problems/statistics-from-a-large-sample Medium
298 Math https://leetcode.com/problems/bulb-switcher-ii Medium
 Crack The Coding Interview - Dinesh Varyani
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# Topic Question Difficulty

1 Hash Table https://leetcode.com/problems/two-sum Easy

2 Hash Table https://leetcode.com/problems/longest-substring-without-repeating-characters Medium
3 Hash Table https://leetcode.com/problems/lru-cache Medium
4 Hash Table https://leetcode.com/problems/subarray-sum-equals-k Medium
5 Hash Table https://leetcode.com/problems/word-break Medium
6 Hash Table https://leetcode.com/problems/minimum-window-substring Hard
7 Hash Table https://leetcode.com/problems/letter-combinations-of-a-phone-number Medium
8 Hash Table https://leetcode.com/problems/first-missing-positive Hard
9 Hash Table https://leetcode.com/problems/longest-consecutive-sequence Medium
10 Hash Table https://leetcode.com/problems/group-anagrams Medium
11 Hash Table https://leetcode.com/problems/intersection-of-two-linked-lists Easy
12 Hash Table https://leetcode.com/problems/majority-element Easy
13 Hash Table https://leetcode.com/problems/construct-binary-tree-from-preorder-and-inorder-traversal
Medium
14 Hash Table https://leetcode.com/problems/top-k-frequent-elements Medium
15 Hash Table https://leetcode.com/problems/copy-list-with-random-pointer Medium
16 Hash Table https://leetcode.com/problems/word-ladder Hard
17 Hash Table https://leetcode.com/problems/linked-list-cycle Easy
18 Hash Table https://leetcode.com/problems/implement-trie-prefix-tree Medium
19 Hash Table https://leetcode.com/problems/partition-labels Medium
20 Hash Table https://leetcode.com/problems/task-scheduler Medium
21 Hash Table https://leetcode.com/problems/find-all-numbers-disappeared-in-an-array Easy
22 Hash Table https://leetcode.com/problems/linked-list-cycle-ii Medium
23 Hash Table https://leetcode.com/problems/find-all-anagrams-in-a-string Medium
24 Hash Table https://leetcode.com/problems/set-matrix-zeroes Medium
25 Hash Table https://leetcode.com/problems/find-all-duplicates-in-an-array Medium
26 Hash Table https://leetcode.com/problems/insert-delete-getrandom-o1 Medium
27 Hash Table https://leetcode.com/problems/missing-number Easy
28 Hash Table https://leetcode.com/problems/clone-graph Medium
29 Hash Table https://leetcode.com/problems/happy-number Easy
30 Hash Table https://leetcode.com/problems/first-unique-character-in-a-string Easy
31 Hash Table https://leetcode.com/problems/word-break-ii Hard
32 Hash Table https://leetcode.com/problems/valid-sudoku Medium
33 Hash Table https://leetcode.com/problems/reorganize-string Medium
34 Hash Table https://leetcode.com/problems/permutation-in-string Medium
35 Hash Table https://leetcode.com/problems/majority-element-ii Medium
36 Hash Table https://leetcode.com/problems/construct-binary-tree-from-inorder-and-postorder-traversal
Medium
37 Hash Table https://leetcode.com/problems/top-k-frequent-words Medium
38 Hash Table https://leetcode.com/problems/valid-anagram Easy
39 Hash Table https://leetcode.com/problems/intersection-of-two-arrays-ii Easy
40 Hash Table https://leetcode.com/problems/contiguous-array Medium
41 Hash Table https://leetcode.com/problems/sort-characters-by-frequency Medium
42 Hash Table https://leetcode.com/problems/longest-repeating-character-replacement Medium
43 Hash Table https://leetcode.com/problems/ugly-number-ii Medium
44 Hash Table https://leetcode.com/problems/longest-substring-with-at-least-k-repeating-characters
Medium
45 Hash Table https://leetcode.com/problems/word-ladder-ii Hard
46 Hash Table https://leetcode.com/problems/contains-duplicate Easy
47 Hash Table https://leetcode.com/problems/jewels-and-stones Easy
48 Hash Table https://leetcode.com/problems/two-sum-iv-input-is-a-bst Easy
49 Hash Table https://leetcode.com/problems/isomorphic-strings Easy
50 Hash Table https://leetcode.com/problems/delete-and-earn Medium
51 Hash Table https://leetcode.com/problems/longest-string-chain Medium
52 Hash Table https://leetcode.com/problems/lfu-cache Hard
53 Hash Table https://leetcode.com/problems/pairs-of-songs-with-total-durations-divisible-by-60Medium
54 Hash Table https://leetcode.com/problems/maximum-xor-of-two-numbers-in-an-array Medium
55 Hash Table https://leetcode.com/problems/roman-to-integer Easy
56 Hash Table https://leetcode.com/problems/find-the-town-judge Easy
57 Hash Table https://leetcode.com/problems/4sum-ii Medium
58 Hash Table https://leetcode.com/problems/how-many-numbers-are-smaller-than-the-current-number
Easy
59 Hash Table https://leetcode.com/problems/integer-to-roman Medium
60 Hash Table https://leetcode.com/problems/subarrays-with-k-different-integers Hard
61 Hash Table https://leetcode.com/problems/word-pattern Easy
 62 Hash Table https://leetcode.com/problems/vertical-order-traversal-of-a-binary-tree Hard
63 Hash Table https://leetcode.com/problems/number-of-matching-subsequences Medium
64 Hash Table https://leetcode.com/problems/open-the-lock Medium
65 Hash Table https://leetcode.com/problems/palindrome-pairs Hard
66 Hash Table https://leetcode.com/problems/verifying-an-alien-dictionary Easy
67 Hash Table https://leetcode.com/problems/subarray-sums-divisible-by-k Medium
68 Hash Table https://leetcode.com/problems/maximum-frequency-stack Hard
69 Hash Table https://leetcode.com/problems/intersection-of-two-arrays Easy
70 Hash Table https://leetcode.com/problems/longest-palindrome Easy
71 Hash Table https://leetcode.com/problems/design-hashmap Easy
72 Hash Table https://leetcode.com/problems/find-common-characters Easy
73 Hash Table https://leetcode.com/problems/contains-duplicate-ii Easy
74 Hash Table https://leetcode.com/problems/number-of-good-pairs Easy
75 Hash Table https://leetcode.com/problems/split-array-into-consecutive-subsequences Medium
76 Hash Table https://leetcode.com/problems/sliding-window-median Hard
77 Hash Table https://leetcode.com/problems/smallest-range-covering-elements-from-k-lists Hard
78 Hash Table https://leetcode.com/problems/longest-arithmetic-subsequence Medium
79 Hash Table https://leetcode.com/problems/time-based-key-value-store Medium
80 Hash Table https://leetcode.com/problems/design-twitter Medium
81 Hash Table https://leetcode.com/problems/degree-of-an-array Easy
82 Hash Table https://leetcode.com/problems/find-the-difference Easy
83 Hash Table https://leetcode.com/problems/smallest-subtree-with-all-the-deepest-nodes Medium
84 Hash Table https://leetcode.com/problems/custom-sort-string Medium
85 Hash Table https://leetcode.com/problems/brick-wall Medium
86 Hash Table https://leetcode.com/problems/next-greater-element-i Easy
87 Hash Table https://leetcode.com/problems/construct-binary-tree-from-preorder-and-postorder-traversal
Medium
88 Hash Table https://leetcode.com/problems/repeated-dna-sequences Medium
89 Hash Table https://leetcode.com/problems/substring-with-concatenation-of-all-words Hard
90 Hash Table https://leetcode.com/problems/bus-routes Hard
91 Hash Table https://leetcode.com/problems/find-and-replace-pattern Medium
92 Hash Table https://leetcode.com/problems/set-mismatch Easy
93 Hash Table https://leetcode.com/problems/unique-email-addresses Easy
94 Hash Table https://leetcode.com/problems/k-diff-pairs-in-an-array Medium
95 Hash Table https://leetcode.com/problems/relative-sort-array Easy
96 Hash Table https://leetcode.com/problems/insert-delete-getrandom-o1-duplicates-allowed Hard
97 Hash Table https://leetcode.com/problems/number-of-submatrices-that-sum-to-target Hard
98 Hash Table https://leetcode.com/problems/fraction-to-recurring-decimal Medium
99 Hash Table https://leetcode.com/problems/longest-harmonious-subsequence Easy
100 Hash Table https://leetcode.com/problems/employee-importance Medium
101 Hash Table https://leetcode.com/problems/count-number-of-nice-subarrays Medium
102 Hash Table https://leetcode.com/problems/ransom-note Easy
103 Hash Table https://leetcode.com/problems/minimum-operations-to-reduce-x-to-zero Medium
104 Hash Table https://leetcode.com/problems/replace-words Medium
105 Hash Table https://leetcode.com/problems/increasing-subsequences Medium
106 Hash Table https://leetcode.com/problems/snapshot-array Medium
107 Hash Table https://leetcode.com/problems/length-of-longest-fibonacci-subsequence Medium
108 Hash Table https://leetcode.com/problems/minimum-area-rectangle Medium
109 Hash Table https://leetcode.com/problems/most-frequent-subtree-sum Medium
110 Hash Table https://leetcode.com/problems/super-ugly-number Medium
111 Hash Table https://leetcode.com/problems/buddy-strings Easy
112 Hash Table https://leetcode.com/problems/smallest-string-with-swaps Medium
113 Hash Table https://leetcode.com/problems/remove-zero-sum-consecutive-nodes-from-linked-list
Medium
114 Hash Table https://leetcode.com/problems/continuous-subarray-sum Medium
115 Hash Table https://leetcode.com/problems/bulls-and-cows Medium
116 Hash Table https://leetcode.com/problems/hand-of-straights Medium
117 Hash Table https://leetcode.com/problems/delete-leaves-with-a-given-value Medium
118 Hash Table https://leetcode.com/problems/longest-word-in-dictionary Medium
119 Hash Table https://leetcode.com/problems/number-of-substrings-containing-all-three-characters
Medium
120 Hash Table https://leetcode.com/problems/most-common-word Easy
121 Hash Table https://leetcode.com/problems/prison-cells-after-n-days Medium
122 Hash Table https://leetcode.com/problems/binary-subarrays-with-sum Medium
123 Hash Table https://leetcode.com/problems/unique-morse-code-words Easy
124 Hash Table https://leetcode.com/problems/map-sum-pairs Medium
125 Hash Table https://leetcode.com/problems/x-of-a-kind-in-a-deck-of-cards Easy
126 Hash Table https://leetcode.com/problems/unique-number-of-occurrences Easy
127 Hash Table https://leetcode.com/problems/encode-and-decode-tinyurl Medium
128 Hash Table https://leetcode.com/problems/fair-candy-swap Easy
129 Hash Table https://leetcode.com/problems/design-hashset Easy
130 Hash Table https://leetcode.com/problems/reduce-array-size-to-the-half Medium
131 Hash Table https://leetcode.com/problems/find-two-non-overlapping-sub-arrays-each-with-target-sum
Medium
132 Hash Table https://leetcode.com/problems/design-underground-system Medium
133 Hash Table https://leetcode.com/problems/minimum-index-sum-of-two-lists Easy
134 Hash Table https://leetcode.com/problems/number-of-valid-words-for-each-puzzle Hard
135 Hash Table https://leetcode.com/problems/sort-array-by-increasing-frequency Easy
136 Hash Table https://leetcode.com/problems/lowest-common-ancestor-of-deepest-leaves Medium
137 Hash Table https://leetcode.com/problems/minimum-number-of-steps-to-make-two-strings-anagramMedium
138 Hash Table https://leetcode.com/problems/all-oone-data-structure Hard
139 Hash Table https://leetcode.com/problems/find-the-longest-substring-containing-vowels-in-even-counts
Medium
140 Hash Table https://leetcode.com/problems/divide-array-in-sets-of-k-consecutive-numbers Medium
141 Hash Table https://leetcode.com/problems/array-of-doubled-pairs Medium
142 Hash Table https://leetcode.com/problems/subdomain-visit-count Medium
143 Hash Table https://leetcode.com/problems/smallest-integer-divisible-by-k Medium
144 Hash Table https://leetcode.com/problems/jump-game-iv Hard
145 Hash Table https://leetcode.com/problems/implement-magic-dictionary Medium
146 Hash Table https://leetcode.com/problems/maximum-number-of-balloons Easy
147 Hash Table https://leetcode.com/problems/word-subsets Medium
148 Hash Table https://leetcode.com/problems/distribute-candies Easy
149 Hash Table https://leetcode.com/problems/group-the-people-given-the-group-size-they-belong-to
Medium
150 Hash Table https://leetcode.com/problems/find-words-that-can-be-formed-by-characters Easy
151 Hash Table https://leetcode.com/problems/3sum-with-multiplicity Medium
152 Hash Table https://leetcode.com/problems/longest-well-performing-interval Medium
153 Hash Table https://leetcode.com/problems/avoid-flood-in-the-city Medium
154 Hash Table https://leetcode.com/problems/random-pick-index Medium
155 Hash Table https://leetcode.com/problems/number-of-atoms Hard
156 Hash Table https://leetcode.com/problems/destination-city Easy
157 Hash Table https://leetcode.com/problems/minimum-time-to-collect-all-apples-in-a-tree Medium
158 Hash Table https://leetcode.com/problems/uncommon-words-from-two-sentences Easy
159 Hash Table https://leetcode.com/problems/longest-arithmetic-subsequence-of-given-difference Medium
160 Hash Table https://leetcode.com/problems/keyboard-row Easy
161 Hash Table https://leetcode.com/problems/n-repeated-element-in-size-2n-array Easy
162 Hash Table https://leetcode.com/problems/binary-trees-with-factors Medium
163 Hash Table https://leetcode.com/problems/count-triplets-that-can-form-two-arrays-of-equal-xor
Medium
164 Hash Table https://leetcode.com/problems/make-sum-divisible-by-p Medium
165 Hash Table https://leetcode.com/problems/find-duplicate-file-in-system Medium
166 Hash Table https://leetcode.com/problems/rank-transform-of-an-array Easy
167 Hash Table https://leetcode.com/problems/distant-barcodes Medium
168 Hash Table https://leetcode.com/problems/max-points-on-a-line Hard
169 Hash Table https://leetcode.com/problems/check-if-array-pairs-are-divisible-by-k Medium
170 Hash Table https://leetcode.com/problems/minimum-genetic-mutation Medium
171 Hash Table https://leetcode.com/problems/maximum-erasure-value Medium
172 Hash Table https://leetcode.com/problems/least-number-of-unique-integers-after-k-removalsMedium
173 Hash Table https://leetcode.com/problems/find-winner-on-a-tic-tac-toe-game Easy
174 Hash Table https://leetcode.com/problems/rank-teams-by-votes Medium
175 Hash Table https://leetcode.com/problems/short-encoding-of-words Medium
176 Hash Table https://leetcode.com/problems/check-if-n-and-its-double-exist Easy
177 Hash Table https://leetcode.com/problems/maximum-number-of-non-overlapping-subarrays-with-sum-equals-target
Medium
178 Hash Table https://leetcode.com/problems/count-the-number-of-consistent-strings Easy
179 Hash Table https://leetcode.com/problems/check-if-a-string-contains-all-binary-codes-of-size-k
Medium
180 Hash Table https://leetcode.com/problems/linked-list-components Medium
181 Hash Table https://leetcode.com/problems/online-election Medium
182 Hash Table https://leetcode.com/problems/check-array-formation-through-concatenation Easy
183 Hash Table https://leetcode.com/problems/max-number-of-k-sum-pairs Medium
184 Hash Table https://leetcode.com/problems/make-two-arrays-equal-by-reversing-sub-arrays Easy
185 Hash Table https://leetcode.com/problems/fruit-into-baskets Medium
186 Hash Table https://leetcode.com/problems/construct-k-palindrome-strings Medium
187 Hash Table https://leetcode.com/problems/alphabet-board-path Medium
188 Hash Table https://leetcode.com/problems/determine-if-two-strings-are-close Medium
189 Hash Table https://leetcode.com/problems/sum-of-unique-elements Easy
190 Hash Table https://leetcode.com/problems/rabbits-in-forest Medium
191 Hash Table https://leetcode.com/problems/random-pick-with-blacklist Hard
192 Hash Table https://leetcode.com/problems/number-of-boomerangs Medium
193 Hash Table https://leetcode.com/problems/find-lucky-integer-in-an-array Easy
194 Hash Table https://leetcode.com/problems/number-of-wonderful-substrings Medium
195 Hash Table https://leetcode.com/problems/restore-the-array-from-adjacent-pairs Medium
196 Hash Table https://leetcode.com/problems/check-if-the-sentence-is-pangram Easy
197 Hash Table https://leetcode.com/problems/count-substrings-that-differ-by-one-character Medium
198 Hash Table https://leetcode.com/problems/maximum-number-of-occurrences-of-a-substring Medium
199 Hash Table https://leetcode.com/problems/reconstruct-original-digits-from-english Medium
200 Hash Table https://leetcode.com/problems/can-make-palindrome-from-substring Medium
201 Hash Table https://leetcode.com/problems/split-a-string-into-the-max-number-of-unique-substrings
Medium
202 Hash Table https://leetcode.com/problems/flip-columns-for-maximum-number-of-equal-rowsMedium
203 Hash Table https://leetcode.com/problems/increasing-decreasing-string Easy
204 Hash Table https://leetcode.com/problems/find-longest-awesome-substring Hard
205 Hash Table https://leetcode.com/problems/compare-strings-by-frequency-of-the-smallest-character
Medium
206 Hash Table https://leetcode.com/problems/count-good-meals Medium
207 Hash Table https://leetcode.com/problems/number-of-equivalent-domino-pairs Easy
208 Hash Table https://leetcode.com/problems/path-crossing Easy
209 Hash Table https://leetcode.com/problems/equal-sum-arrays-with-minimum-number-of-operationsMedium
210 Hash Table https://leetcode.com/problems/escape-a-large-maze Hard
211 Hash Table https://leetcode.com/problems/longest-nice-substring Easy
212 Hash Table https://leetcode.com/problems/groups-of-special-equivalent-strings Medium
213 Hash Table https://leetcode.com/problems/substrings-of-size-three-with-distinct-characters Easy
214 Hash Table https://leetcode.com/problems/cinema-seat-allocation Medium
215 Hash Table https://leetcode.com/problems/minimum-moves-to-make-array-complementary Medium
216 Hash Table https://leetcode.com/problems/parse-lisp-expression Hard
217 Hash Table https://leetcode.com/problems/largest-color-value-in-a-directed-graph Hard
218 Hash Table https://leetcode.com/problems/unique-length-3-palindromic-subsequences Medium
219 Hash Table https://leetcode.com/problems/grid-illumination Hard
220 Hash Table https://leetcode.com/problems/minimum-operations-to-make-a-subsequence Hard
221 Hash Table https://leetcode.com/problems/tuple-with-same-product Medium
222 Hash Table https://leetcode.com/problems/find-original-array-from-doubled-array Medium
223 Hash Table https://leetcode.com/problems/longest-uncommon-subsequence-ii Medium
224 Hash Table https://leetcode.com/problems/count-nice-pairs-in-an-array Medium
225 Hash Table https://leetcode.com/problems/maximum-equal-frequency Hard
226 Hash Table https://leetcode.com/problems/vowel-spellchecker Medium
227 Hash Table https://leetcode.com/problems/largest-substring-between-two-equal-characters Easy
228 Hash Table https://leetcode.com/problems/intervals-between-identical-elements Medium
229 Hash Table https://leetcode.com/problems/minimum-absolute-difference-queries Medium
230 Hash Table https://leetcode.com/problems/maximum-number-of-balls-in-a-box Easy
231 Hash Table https://leetcode.com/problems/finding-the-users-active-minutes Medium
232 Hash Table https://leetcode.com/problems/dinner-plate-stacks Hard
233 Hash Table https://leetcode.com/problems/check-if-one-string-swap-can-make-strings-equal Easy
234 Hash Table https://leetcode.com/problems/making-file-names-unique Medium
235 Hash Table https://leetcode.com/problems/shortest-completing-word Easy
236 Hash Table https://leetcode.com/problems/circular-array-loop Medium
237 Hash Table https://leetcode.com/problems/random-flip-matrix Medium
238 Hash Table https://leetcode.com/problems/number-of-different-integers-in-a-string Easy
239 Hash Table https://leetcode.com/problems/range-frequency-queries Medium
240 Hash Table https://leetcode.com/problems/sum-of-beauty-of-all-substrings Medium
241 Hash Table https://leetcode.com/problems/largest-values-from-labels Medium
242 Hash Table https://leetcode.com/problems/can-convert-string-in-k-moves Medium
243 Hash Table https://leetcode.com/problems/find-all-possible-recipes-from-given-supplies Medium
244 Hash Table https://leetcode.com/problems/invalid-transactions Medium
245 Hash Table https://leetcode.com/problems/evaluate-the-bracket-pairs-of-a-string Medium
246 Hash Table https://leetcode.com/problems/finding-pairs-with-a-certain-sum Medium
247 Hash Table https://leetcode.com/problems/count-vowel-substrings-of-a-string Easy
248 Hash Table https://leetcode.com/problems/stock-price-fluctuation Medium
249 Hash Table https://leetcode.com/problems/count-largest-group Easy
250 Hash Table https://leetcode.com/problems/check-if-all-characters-have-equal-number-of-occurrences
Easy
251 Hash Table https://leetcode.com/problems/redistribute-characters-to-make-all-strings-equal Easy
252 Hash Table https://leetcode.com/problems/maximum-number-of-ways-to-partition-an-array Hard
253 Hash Table https://leetcode.com/problems/people-whose-list-of-favorite-companies-is-not-a-subset-of-another-list
Medium
254 Hash Table https://leetcode.com/problems/powerful-integers Medium
255 Hash Table https://leetcode.com/problems/find-subsequence-of-length-k-with-the-largest-sum Easy
256 Hash Table https://leetcode.com/problems/number-of-ways-where-square-of-number-is-equal-to-product-of-two-numbers
Medium
257 Hash Table https://leetcode.com/problems/maximum-number-of-words-you-can-type Easy
258 Hash Table https://leetcode.com/problems/triples-with-bitwise-and-equal-to-zero Hard
259 Hash Table https://leetcode.com/problems/check-if-all-the-integers-in-a-range-are-covered Easy
260 Hash Table https://leetcode.com/problems/second-largest-digit-in-a-string Easy
261 Hash Table https://leetcode.com/problems/change-minimum-characters-to-satisfy-one-of-three-conditions
Medium
262 Hash Table https://leetcode.com/problems/get-watched-videos-by-your-friends Medium
263 Hash Table https://leetcode.com/problems/two-out-of-three Easy
264 Hash Table https://leetcode.com/problems/merge-bsts-to-create-single-bst Hard
265 Hash Table https://leetcode.com/problems/number-of-pairs-of-interchangeable-rectangles Medium
266 Hash Table https://leetcode.com/problems/display-table-of-food-orders-in-a-restaurant Medium
267 Hash Table https://leetcode.com/problems/detect-squares Medium
268 Hash Table https://leetcode.com/problems/kth-distinct-string-in-an-array Easy
269 Hash Table https://leetcode.com/problems/design-an-ordered-stream Easy
270 Hash Table https://leetcode.com/problems/operations-on-tree Medium
271 Hash Table https://leetcode.com/problems/rings-and-rods Easy
272 Hash Table https://leetcode.com/problems/throne-inheritance Medium
273 Hash Table https://leetcode.com/problems/count-common-words-with-one-occurrence Easy
274 Hash Table https://leetcode.com/problems/recover-the-original-array Hard
275 Hash Table https://leetcode.com/problems/alert-using-same-key-card-three-or-more-times-in-a-one-hour-period
Medium
276 Hash Table https://leetcode.com/problems/delete-duplicate-folders-in-system Hard
277 Hash Table https://leetcode.com/problems/finding-3-digit-even-numbers Easy
278 Hash Table https://leetcode.com/problems/html-entity-parser Medium
279 Hash Table https://leetcode.com/problems/design-authentication-manager Medium
280 Hash Table https://leetcode.com/problems/design-movie-rental-system Hard
281 Hash Table https://leetcode.com/problems/check-whether-two-strings-are-almost-equivalent Easy
282 Hash Table https://leetcode.com/problems/basic-calculator-iv Hard
283 Hash Table https://leetcode.com/problems/apply-discount-every-n-orders Medium
284 Hash Table https://leetcode.com/problems/card-flipping-game Medium
285 Hash Table https://leetcode.com/problems/tweet-counts-per-frequency Medium
286 Hash Table https://leetcode.com/problems/simple-bank-system Medium
 Crack The Coding Interview - Dinesh Varyani
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# Topic Question Difficulty

1 Sorting https://leetcode.com/problems/3sum Medium

2 Sorting https://leetcode.com/problems/merge-intervals Medium
3 Sorting https://leetcode.com/problems/sort-colors Medium
4 Sorting https://leetcode.com/problems/kth-largest-element-in-an-array Medium
5 Sorting https://leetcode.com/problems/group-anagrams Medium
6 Sorting https://leetcode.com/problems/majority-element Easy
7 Sorting https://leetcode.com/problems/top-k-frequent-elements Medium
8 Sorting https://leetcode.com/problems/find-median-from-data-stream Hard
9 Sorting https://leetcode.com/problems/task-scheduler Medium
10 Sorting https://leetcode.com/problems/sort-list Medium
11 Sorting https://leetcode.com/problems/kth-smallest-element-in-a-sorted-matrix Medium
12 Sorting https://leetcode.com/problems/4sum Medium
13 Sorting https://leetcode.com/problems/3sum-closest Medium
14 Sorting https://leetcode.com/problems/k-closest-points-to-origin Medium
15 Sorting https://leetcode.com/problems/shortest-unsorted-continuous-subarray Medium
16 Sorting https://leetcode.com/problems/queue-reconstruction-by-height Medium
17 Sorting https://leetcode.com/problems/missing-number Easy
18 Sorting https://leetcode.com/problems/largest-number Medium
19 Sorting https://leetcode.com/problems/squares-of-a-sorted-array Easy
20 Sorting https://leetcode.com/problems/reorganize-string Medium
21 Sorting https://leetcode.com/problems/majority-element-ii Medium
22 Sorting https://leetcode.com/problems/top-k-frequent-words Medium
23 Sorting https://leetcode.com/problems/valid-anagram Easy
24 Sorting https://leetcode.com/problems/intersection-of-two-arrays-ii Easy
25 Sorting https://leetcode.com/problems/find-k-closest-elements Medium
26 Sorting https://leetcode.com/problems/sort-characters-by-frequency Medium
27 Sorting https://leetcode.com/problems/contains-duplicate Easy
28 Sorting https://leetcode.com/problems/non-overlapping-intervals Medium
29 Sorting https://leetcode.com/problems/largest-divisible-subset Medium
30 Sorting https://leetcode.com/problems/russian-doll-envelopes Hard
31 Sorting https://leetcode.com/problems/maximum-profit-in-job-scheduling Hard
32 Sorting https://leetcode.com/problems/merge-sorted-array Easy
33 Sorting https://leetcode.com/problems/how-many-numbers-are-smaller-than-the-current-number
Easy
34 Sorting https://leetcode.com/problems/number-of-matching-subsequences Medium
35 Sorting https://leetcode.com/problems/minimum-number-of-arrows-to-burst-balloons Medium
36 Sorting https://leetcode.com/problems/sort-array-by-parity Easy
37 Sorting https://leetcode.com/problems/maximum-product-of-three-numbers Easy
38 Sorting https://leetcode.com/problems/two-city-scheduling Medium
39 Sorting https://leetcode.com/problems/intersection-of-two-arrays Easy
40 Sorting https://leetcode.com/problems/valid-triangle-number Medium
41 Sorting https://leetcode.com/problems/contains-duplicate-iii Medium
42 Sorting https://leetcode.com/problems/maximum-length-of-pair-chain Medium
43 Sorting https://leetcode.com/problems/wiggle-sort-ii Medium
44 Sorting https://leetcode.com/problems/smallest-range-covering-elements-from-k-lists Hard
45 Sorting https://leetcode.com/problems/maximum-gap Hard
46 Sorting https://leetcode.com/problems/insertion-sort-list Medium
47 Sorting https://leetcode.com/problems/car-pooling Medium
48 Sorting https://leetcode.com/problems/find-the-difference Easy
49 Sorting https://leetcode.com/problems/find-k-th-smallest-pair-distance Hard
50 Sorting https://leetcode.com/problems/custom-sort-string Medium
51 Sorting https://leetcode.com/problems/reveal-cards-in-increasing-order Medium
52 Sorting https://leetcode.com/problems/boats-to-save-people Medium
53 Sorting https://leetcode.com/problems/sort-an-array Medium
54 Sorting https://leetcode.com/problems/set-mismatch Easy
55 Sorting https://leetcode.com/problems/max-chunks-to-make-sorted Medium
56 Sorting https://leetcode.com/problems/sort-array-by-parity-ii Easy
57 Sorting https://leetcode.com/problems/k-diff-pairs-in-an-array Medium
58 Sorting https://leetcode.com/problems/minimum-cost-to-hire-k-workers Hard
59 Sorting https://leetcode.com/problems/reorder-data-in-log-files Easy
60 Sorting https://leetcode.com/problems/relative-sort-array Easy
61 Sorting https://leetcode.com/problems/third-maximum-number Easy
 62 Sorting https://leetcode.com/problems/longest-harmonious-subsequence Easy
63 Sorting https://leetcode.com/problems/sort-the-matrix-diagonally Medium
64 Sorting https://leetcode.com/problems/all-elements-in-two-binary-search-trees Medium
65 Sorting https://leetcode.com/problems/the-k-weakest-rows-in-a-matrix Easy
66 Sorting https://leetcode.com/problems/minimum-absolute-difference Easy
67 Sorting https://leetcode.com/problems/minimum-area-rectangle Medium
68 Sorting https://leetcode.com/problems/longest-word-in-dictionary-through-deleting Medium
69 Sorting https://leetcode.com/problems/maximum-units-on-a-truck Easy
70 Sorting https://leetcode.com/problems/assign-cookies Easy
71 Sorting https://leetcode.com/problems/hand-of-straights Medium
72 Sorting https://leetcode.com/problems/minimum-moves-to-equal-array-elements-ii Medium
73 Sorting https://leetcode.com/problems/longest-word-in-dictionary Medium
74 Sorting https://leetcode.com/problems/heaters Medium
75 Sorting https://leetcode.com/problems/advantage-shuffle Medium
76 Sorting https://leetcode.com/problems/car-fleet Medium
77 Sorting https://leetcode.com/problems/h-index Medium
78 Sorting https://leetcode.com/problems/fair-candy-swap Easy
79 Sorting https://leetcode.com/problems/reduce-array-size-to-the-half Medium
80 Sorting https://leetcode.com/problems/maximum-performance-of-a-team Hard
81 Sorting https://leetcode.com/problems/find-right-interval Medium
82 Sorting https://leetcode.com/problems/sort-array-by-increasing-frequency Easy
83 Sorting https://leetcode.com/problems/pancake-sorting Medium
84 Sorting https://leetcode.com/problems/minimum-deletions-to-make-character-frequencies-unique
Medium
85 Sorting https://leetcode.com/problems/divide-array-in-sets-of-k-consecutive-numbers Medium
86 Sorting https://leetcode.com/problems/smallest-range-ii Medium
87 Sorting https://leetcode.com/problems/max-chunks-to-make-sorted-ii Hard
88 Sorting https://leetcode.com/problems/array-of-doubled-pairs Medium
89 Sorting https://leetcode.com/problems/maximum-area-of-a-piece-of-cake-after-horizontal-and-vertical-cuts
Medium
90 Sorting https://leetcode.com/problems/minimum-increment-to-make-array-unique Medium
91 Sorting https://leetcode.com/problems/minimum-difference-between-largest-and-smallest-value-in-three-moves
Medium
92 Sorting https://leetcode.com/problems/magnetic-force-between-two-balls Medium
93 Sorting https://leetcode.com/problems/number-of-subsequences-that-satisfy-the-given-sum-condition
Medium
94 Sorting https://leetcode.com/problems/frequency-of-the-most-frequent-element Medium
95 Sorting https://leetcode.com/problems/3sum-with-multiplicity Medium
96 Sorting https://leetcode.com/problems/minimum-time-difference Medium
97 Sorting https://leetcode.com/problems/maximize-sum-of-array-after-k-negations Easy
98 Sorting https://leetcode.com/problems/remove-covered-intervals Medium
99 Sorting https://leetcode.com/problems/sort-integers-by-the-number-of-1-bits Easy
100 Sorting https://leetcode.com/problems/reducing-dishes Hard
101 Sorting https://leetcode.com/problems/largest-perimeter-triangle Easy
102 Sorting https://leetcode.com/problems/rank-transform-of-an-array Easy
103 Sorting https://leetcode.com/problems/distant-barcodes Medium
104 Sorting https://leetcode.com/problems/maximum-product-of-two-elements-in-an-array Easy
105 Sorting https://leetcode.com/problems/diagonal-traverse-ii Medium
106 Sorting https://leetcode.com/problems/sort-integers-by-the-power-value Medium
107 Sorting https://leetcode.com/problems/most-profit-assigning-work Medium
108 Sorting https://leetcode.com/problems/least-number-of-unique-integers-after-k-removalsMedium
109 Sorting https://leetcode.com/problems/best-team-with-no-conflicts Medium
110 Sorting https://leetcode.com/problems/ipo Hard
111 Sorting https://leetcode.com/problems/rank-teams-by-votes Medium
112 Sorting https://leetcode.com/problems/check-if-n-and-its-double-exist Easy
113 Sorting https://leetcode.com/problems/single-threaded-cpu Medium
114 Sorting https://leetcode.com/problems/sorting-the-sentence Easy
115 Sorting https://leetcode.com/problems/find-and-replace-in-string Medium
116 Sorting https://leetcode.com/problems/sum-of-mutated-array-closest-to-target Medium
117 Sorting https://leetcode.com/problems/allocate-mailboxes Hard
118 Sorting https://leetcode.com/problems/array-partition-i Easy
119 Sorting https://leetcode.com/problems/bag-of-tokens Medium
120 Sorting https://leetcode.com/problems/max-number-of-k-sum-pairs Medium
121 Sorting https://leetcode.com/problems/make-two-arrays-equal-by-reversing-sub-arrays Easy
122 Sorting https://leetcode.com/problems/determine-if-two-strings-are-close Medium
123 Sorting https://leetcode.com/problems/largest-number-at-least-twice-of-others Easy
124 Sorting https://leetcode.com/problems/sell-diminishing-valued-colored-balls Medium
125 Sorting https://leetcode.com/problems/largest-submatrix-with-rearrangements Medium
126 Sorting https://leetcode.com/problems/jump-game-v Hard
127 Sorting https://leetcode.com/problems/random-pick-with-blacklist Hard
128 Sorting https://leetcode.com/problems/special-array-with-x-elements-greater-than-or-equal-x
Easy
129 Sorting https://leetcode.com/problems/reordered-power-of-2 Medium
130 Sorting https://leetcode.com/problems/orderly-queue Hard
131 Sorting https://leetcode.com/problems/maximum-number-of-coins-you-can-get Medium
132 Sorting https://leetcode.com/problems/can-make-arithmetic-progression-from-sequence Easy
133 Sorting https://leetcode.com/problems/friends-of-appropriate-ages Medium
134 Sorting https://leetcode.com/problems/range-sum-of-sorted-subarray-sums Medium
135 Sorting https://leetcode.com/problems/minimize-maximum-pair-sum-in-array Medium
136 Sorting https://leetcode.com/problems/the-number-of-weak-characters-in-the-game Medium
137 Sorting https://leetcode.com/problems/compare-strings-by-frequency-of-the-smallest-character
Medium
138 Sorting https://leetcode.com/problems/arithmetic-subarrays Medium
139 Sorting https://leetcode.com/problems/check-if-a-string-can-break-another-string Medium
140 Sorting https://leetcode.com/problems/matrix-cells-in-distance-order Easy
141 Sorting https://leetcode.com/problems/maximum-sum-obtained-of-any-permutation Medium
142 Sorting https://leetcode.com/problems/rearrange-words-in-a-sentence Medium
143 Sorting https://leetcode.com/problems/sum-of-subsequence-widths Hard
144 Sorting https://leetcode.com/problems/set-intersection-size-at-least-two Hard
145 Sorting https://leetcode.com/problems/checking-existence-of-edge-length-limited-paths Hard
146 Sorting https://leetcode.com/problems/stone-game-vi Medium
147 Sorting https://leetcode.com/problems/maximum-height-by-stacking-cuboids Hard
148 Sorting https://leetcode.com/problems/average-salary-excluding-the-minimum-and-maximum-salary
Easy
149 Sorting https://leetcode.com/problems/minimum-absolute-sum-difference Medium
150 Sorting https://leetcode.com/problems/find-critical-and-pseudo-critical-edges-in-minimum-spanning-tree
Hard
151 Sorting https://leetcode.com/problems/maximum-earnings-from-taxi Medium
152 Sorting https://leetcode.com/problems/the-k-strongest-values-in-an-array Medium
153 Sorting https://leetcode.com/problems/find-original-array-from-doubled-array Medium
154 Sorting https://leetcode.com/problems/longest-uncommon-subsequence-ii Medium
155 Sorting https://leetcode.com/problems/minimum-initial-energy-to-finish-tasks Hard
156 Sorting https://leetcode.com/problems/maximum-number-of-visible-points Hard
157 Sorting https://leetcode.com/problems/check-if-string-is-transformable-with-substring-sort-operations
Hard
158 Sorting https://leetcode.com/problems/minimum-interval-to-include-each-query Hard
159 Sorting https://leetcode.com/problems/minimum-subsequence-in-non-increasing-order Easy
160 Sorting https://leetcode.com/problems/height-checker Easy
161 Sorting https://leetcode.com/problems/find-all-people-with-secret Hard
162 Sorting https://leetcode.com/problems/maximum-product-difference-between-two-pairs Easy
163 Sorting https://leetcode.com/problems/relative-ranks Easy
164 Sorting https://leetcode.com/problems/two-best-non-overlapping-events Medium
165 Sorting https://leetcode.com/problems/closest-room Hard
166 Sorting https://leetcode.com/problems/find-the-kth-largest-integer-in-the-array Medium
167 Sorting https://leetcode.com/problems/maximum-ice-cream-bars Medium
168 Sorting https://leetcode.com/problems/reduction-operations-to-make-the-array-elements-equal
Medium
169 Sorting https://leetcode.com/problems/moving-stones-until-consecutive-ii Medium
170 Sorting https://leetcode.com/problems/eliminate-maximum-number-of-monsters Medium
171 Sorting https://leetcode.com/problems/find-target-indices-after-sorting-array Easy
172 Sorting https://leetcode.com/problems/largest-values-from-labels Medium
173 Sorting https://leetcode.com/problems/find-the-distance-value-between-two-arrays Easy
174 Sorting https://leetcode.com/problems/invalid-transactions Medium
175 Sorting https://leetcode.com/problems/minimum-operations-to-make-a-uni-value-grid Medium
176 Sorting https://leetcode.com/problems/mean-of-array-after-removing-some-elements Easy
177 Sorting https://leetcode.com/problems/most-beautiful-item-for-each-query Medium
178 Sorting https://leetcode.com/problems/minimum-space-wasted-from-packaging Hard
179 Sorting https://leetcode.com/problems/gcd-sort-of-an-array Hard
180 Sorting https://leetcode.com/problems/find-subsequence-of-length-k-with-the-largest-sum Easy
181 Sorting https://leetcode.com/problems/array-with-elements-not-equal-to-average-of-neighbors
Medium
182 Sorting https://leetcode.com/problems/minimum-difference-between-highest-and-lowest-of-k-scores
Easy
183 Sorting https://leetcode.com/problems/get-watched-videos-by-your-friends Medium
184 Sorting https://leetcode.com/problems/filter-restaurants-by-vegan-friendly-price-and-distance
Medium
185 Sorting https://leetcode.com/problems/display-table-of-food-orders-in-a-restaurant Medium
186 Sorting https://leetcode.com/problems/minimum-number-of-moves-to-seat-everyone Easy
187 Sorting https://leetcode.com/problems/maximum-number-of-tasks-you-can-assign Hard
188 Sorting https://leetcode.com/problems/maximum-element-after-decreasing-and-rearranging Medium
189 Sorting https://leetcode.com/problems/recover-the-original-array Hard
190 Sorting https://leetcode.com/problems/alert-using-same-key-card-three-or-more-times-in-a-one-hour-period
Medium
191 Sorting https://leetcode.com/problems/widest-vertical-area-between-two-points-containing-no-points
Medium
192 Sorting https://leetcode.com/problems/finding-3-digit-even-numbers Easy
193 Sorting https://leetcode.com/problems/get-biggest-three-rhombus-sums-in-a-grid Medium
194 Sorting https://leetcode.com/problems/tweet-counts-per-frequency Medium
 Crack The Coding Interview - Dinesh Varyani
https://www.youtube.com/user/hubberspot?sub_confirmation=1

# Topic Question Difficulty

1 Greedy https://leetcode.com/problems/container-with-most-water Medium

2 Greedy https://leetcode.com/problems/jump-game Medium
3 Greedy https://leetcode.com/problems/jump-game-ii Medium
4 Greedy https://leetcode.com/problems/best-time-to-buy-and-sell-stock-ii Medium
5 Greedy https://leetcode.com/problems/partition-labels Medium
6 Greedy https://leetcode.com/problems/task-scheduler Medium
7 Greedy https://leetcode.com/problems/shortest-unsorted-continuous-subarray Medium
8 Greedy https://leetcode.com/problems/queue-reconstruction-by-height Medium
9 Greedy https://leetcode.com/problems/gas-station Medium
10 Greedy https://leetcode.com/problems/remove-k-digits Medium
11 Greedy https://leetcode.com/problems/largest-number Medium
12 Greedy https://leetcode.com/problems/wildcard-matching Hard
13 Greedy https://leetcode.com/problems/split-array-largest-sum Hard
14 Greedy https://leetcode.com/problems/reorganize-string Medium
15 Greedy https://leetcode.com/problems/valid-palindrome-ii Easy
16 Greedy https://leetcode.com/problems/remove-duplicate-letters Medium
17 Greedy https://leetcode.com/problems/best-time-to-buy-and-sell-stock-with-transaction-fee
Medium
18 Greedy https://leetcode.com/problems/increasing-triplet-subsequence Medium
19 Greedy https://leetcode.com/problems/capacity-to-ship-packages-within-d-days Medium
20 Greedy https://leetcode.com/problems/non-overlapping-intervals Medium
21 Greedy https://leetcode.com/problems/valid-parenthesis-string Medium
22 Greedy https://leetcode.com/problems/minimum-cost-tree-from-leaf-values Medium
23 Greedy https://leetcode.com/problems/candy Hard
24 Greedy https://leetcode.com/problems/minimum-number-of-arrows-to-burst-balloons Medium
25 Greedy https://leetcode.com/problems/wiggle-subsequence Medium
26 Greedy https://leetcode.com/problems/two-city-scheduling Medium
27 Greedy https://leetcode.com/problems/longest-palindrome Easy
28 Greedy https://leetcode.com/problems/minimum-number-of-refueling-stops Hard
29 Greedy https://leetcode.com/problems/valid-triangle-number Medium
30 Greedy https://leetcode.com/problems/maximum-swap Medium
31 Greedy https://leetcode.com/problems/can-place-flowers Easy
32 Greedy https://leetcode.com/problems/minimum-add-to-make-parentheses-valid Medium
33 Greedy https://leetcode.com/problems/maximum-length-of-pair-chain Medium
34 Greedy https://leetcode.com/problems/split-array-into-consecutive-subsequences Medium
35 Greedy https://leetcode.com/problems/smallest-range-covering-elements-from-k-lists Hard
36 Greedy https://leetcode.com/problems/course-schedule-iii Hard
37 Greedy https://leetcode.com/problems/boats-to-save-people Medium
38 Greedy https://leetcode.com/problems/max-chunks-to-make-sorted Medium
39 Greedy https://leetcode.com/problems/minimum-domino-rotations-for-equal-row Medium
40 Greedy https://leetcode.com/problems/split-a-string-in-balanced-strings Easy
41 Greedy https://leetcode.com/problems/max-increase-to-keep-city-skyline Medium
42 Greedy https://leetcode.com/problems/di-string-match Easy
43 Greedy https://leetcode.com/problems/minimum-cost-to-hire-k-workers Hard
44 Greedy https://leetcode.com/problems/maximum-number-of-events-that-can-be-attendedMedium
45 Greedy https://leetcode.com/problems/couples-holding-hands Hard
46 Greedy https://leetcode.com/problems/balance-a-binary-search-tree Medium
47 Greedy https://leetcode.com/problems/furthest-building-you-can-reach Medium
48 Greedy https://leetcode.com/problems/smallest-subsequence-of-distinct-characters Medium
49 Greedy https://leetcode.com/problems/minimum-cost-to-move-chips-to-the-same-position Easy
50 Greedy https://leetcode.com/problems/minimum-number-of-taps-to-open-to-water-a-garden Hard
51 Greedy https://leetcode.com/problems/maximum-units-on-a-truck Easy
52 Greedy https://leetcode.com/problems/assign-cookies Easy
53 Greedy https://leetcode.com/problems/hand-of-straights Medium
54 Greedy https://leetcode.com/problems/create-maximum-number Hard
55 Greedy https://leetcode.com/problems/advantage-shuffle Medium
56 Greedy https://leetcode.com/problems/find-the-most-competitive-subsequence Medium
57 Greedy https://leetcode.com/problems/lemonade-change Easy
58 Greedy https://leetcode.com/problems/reduce-array-size-to-the-half Medium
59 Greedy https://leetcode.com/problems/video-stitching Medium
60 Greedy https://leetcode.com/problems/maximum-performance-of-a-team Hard
61 Greedy https://leetcode.com/problems/greatest-sum-divisible-by-three Medium
 62 Greedy https://leetcode.com/problems/patching-array Hard
63 Greedy https://leetcode.com/problems/broken-calculator Medium
64 Greedy https://leetcode.com/problems/pancake-sorting Medium
65 Greedy https://leetcode.com/problems/minimum-deletions-to-make-character-frequencies-unique
Medium
66 Greedy https://leetcode.com/problems/partition-array-into-three-parts-with-equal-sum Easy
67 Greedy https://leetcode.com/problems/divide-array-in-sets-of-k-consecutive-numbers Medium
68 Greedy https://leetcode.com/problems/smallest-range-ii Medium
69 Greedy https://leetcode.com/problems/max-chunks-to-make-sorted-ii Hard
70 Greedy https://leetcode.com/problems/array-of-doubled-pairs Medium
71 Greedy https://leetcode.com/problems/maximum-length-of-subarray-with-positive-productMedium
72 Greedy https://leetcode.com/problems/maximum-area-of-a-piece-of-cake-after-horizontal-and-vertical-cuts
Medium
73 Greedy https://leetcode.com/problems/minimum-increment-to-make-array-unique Medium
74 Greedy https://leetcode.com/problems/minimum-difference-between-largest-and-smallest-value-in-three-moves
Medium
75 Greedy https://leetcode.com/problems/score-after-flipping-matrix Medium
76 Greedy https://leetcode.com/problems/frequency-of-the-most-frequent-element Medium
77 Greedy https://leetcode.com/problems/longest-happy-string Medium
78 Greedy https://leetcode.com/problems/maximum-69-number Easy
79 Greedy https://leetcode.com/problems/avoid-flood-in-the-city Medium
80 Greedy https://leetcode.com/problems/maximize-sum-of-array-after-k-negations Easy
81 Greedy https://leetcode.com/problems/minimum-time-to-make-rope-colorful Medium
82 Greedy https://leetcode.com/problems/monotone-increasing-digits Medium
83 Greedy https://leetcode.com/problems/reducing-dishes Hard
84 Greedy https://leetcode.com/problems/largest-perimeter-triangle Easy
85 Greedy https://leetcode.com/problems/minimum-swaps-to-make-strings-equal Medium
86 Greedy https://leetcode.com/problems/distant-barcodes Medium
87 Greedy https://leetcode.com/problems/find-valid-matrix-given-row-and-column-sums Medium
88 Greedy https://leetcode.com/problems/minimum-number-of-increments-on-subarrays-to-form-a-target-array
Hard
89 Greedy https://leetcode.com/problems/most-profit-assigning-work Medium
90 Greedy https://leetcode.com/problems/integer-replacement Medium
91 Greedy https://leetcode.com/problems/least-number-of-unique-integers-after-k-removalsMedium
92 Greedy https://leetcode.com/problems/ipo Hard
93 Greedy https://leetcode.com/problems/break-a-palindrome Medium
94 Greedy https://leetcode.com/problems/maximum-number-of-non-overlapping-subarrays-with-sum-equals-target
Medium
95 Greedy https://leetcode.com/problems/partitioning-into-minimum-number-of-deci-binary-numbers
Medium
96 Greedy https://leetcode.com/problems/array-partition-i Easy
97 Greedy https://leetcode.com/problems/bag-of-tokens Medium
98 Greedy https://leetcode.com/problems/find-the-minimum-number-of-fibonacci-numbers-whose-sum-is-k
Medium
99 Greedy https://leetcode.com/problems/construct-k-palindrome-strings Medium
100 Greedy https://leetcode.com/problems/rabbits-in-forest Medium
101 Greedy https://leetcode.com/problems/sell-diminishing-valued-colored-balls Medium
102 Greedy https://leetcode.com/problems/minimum-suffix-flips Medium
103 Greedy https://leetcode.com/problems/largest-submatrix-with-rearrangements Medium
104 Greedy https://leetcode.com/problems/minimum-number-of-removals-to-make-mountain-array
Hard
105 Greedy https://leetcode.com/problems/rank-transform-of-a-matrix Hard
106 Greedy https://leetcode.com/problems/minimum-insertions-to-balance-a-parentheses-string
Medium
107 Greedy https://leetcode.com/problems/minimum-number-of-flips-to-make-the-binary-string-alternating
Medium
108 Greedy https://leetcode.com/problems/smallest-string-with-a-given-numeric-value Medium
109 Greedy https://leetcode.com/problems/maximum-number-of-coins-you-can-get Medium
110 Greedy https://leetcode.com/problems/stamping-the-sequence Hard
111 Greedy https://leetcode.com/problems/minimize-deviation-in-array Hard
112 Greedy https://leetcode.com/problems/get-the-maximum-score Hard
113 Greedy https://leetcode.com/problems/super-washing-machines Hard
114 Greedy https://leetcode.com/problems/minimum-sideway-jumps Medium
115 Greedy https://leetcode.com/problems/pizza-with-3n-slices Hard
116 Greedy https://leetcode.com/problems/minimum-number-of-swaps-to-make-the-string-balanced
Medium
117 Greedy https://leetcode.com/problems/minimize-maximum-pair-sum-in-array Medium
118 Greedy https://leetcode.com/problems/the-number-of-weak-characters-in-the-game Medium
119 Greedy https://leetcode.com/problems/check-if-a-string-can-break-another-string Medium
120 Greedy https://leetcode.com/problems/split-two-strings-to-make-palindrome Medium
121 Greedy https://leetcode.com/problems/minimum-operations-to-make-the-array-increasing Easy
122 Greedy https://leetcode.com/problems/maximum-sum-obtained-of-any-permutation Medium
123 Greedy https://leetcode.com/problems/strong-password-checker Hard
124 Greedy https://leetcode.com/problems/string-without-aaa-or-bbb Medium
125 Greedy https://leetcode.com/problems/maximum-number-of-eaten-apples Medium
126 Greedy https://leetcode.com/problems/maximum-average-pass-ratio Medium
127 Greedy https://leetcode.com/problems/maximum-number-of-non-overlapping-substringsHard
128 Greedy https://leetcode.com/problems/delete-columns-to-make-sorted-ii Medium
129 Greedy https://leetcode.com/problems/set-intersection-size-at-least-two Hard
130 Greedy https://leetcode.com/problems/equal-sum-arrays-with-minimum-number-of-operationsMedium
131 Greedy https://leetcode.com/problems/maximum-value-at-a-given-index-in-a-bounded-array Medium
132 Greedy https://leetcode.com/problems/maximum-number-of-consecutive-values-you-can-make Medium
133 Greedy https://leetcode.com/problems/stone-game-vi Medium
134 Greedy https://leetcode.com/problems/maximum-distance-between-a-pair-of-values Medium
135 Greedy https://leetcode.com/problems/maximum-score-from-removing-stones Medium
136 Greedy https://leetcode.com/problems/dota2-senate Medium
137 Greedy https://leetcode.com/problems/longest-chunked-palindrome-decomposition Hard
138 Greedy https://leetcode.com/problems/cinema-seat-allocation Medium
139 Greedy https://leetcode.com/problems/minimum-numbers-of-function-calls-to-make-target-array
Medium
140 Greedy https://leetcode.com/problems/minimum-swaps-to-arrange-a-binary-grid Medium
141 Greedy https://leetcode.com/problems/minimum-adjacent-swaps-for-k-consecutive-onesHard
142 Greedy https://leetcode.com/problems/minimum-operations-to-make-a-subsequence Hard
143 Greedy https://leetcode.com/problems/largest-multiple-of-three Hard
144 Greedy https://leetcode.com/problems/find-original-array-from-doubled-array Medium
145 Greedy https://leetcode.com/problems/minimum-adjacent-swaps-to-reach-the-kth-smallest-number
Medium
146 Greedy https://leetcode.com/problems/maximum-score-from-removing-substrings Medium
147 Greedy https://leetcode.com/problems/minimum-initial-energy-to-finish-tasks Hard
148 Greedy https://leetcode.com/problems/check-if-string-is-transformable-with-substring-sort-operations
Hard
149 Greedy https://leetcode.com/problems/reverse-subarray-to-maximize-array-value Hard
150 Greedy https://leetcode.com/problems/minimum-subsequence-in-non-increasing-order Easy
151 Greedy https://leetcode.com/problems/maximum-number-of-weeks-for-which-you-can-work Medium
152 Greedy https://leetcode.com/problems/largest-merge-of-two-strings Medium
153 Greedy https://leetcode.com/problems/reconstruct-a-2-row-binary-matrix Medium
154 Greedy https://leetcode.com/problems/largest-odd-number-in-string Easy
155 Greedy https://leetcode.com/problems/minimum-possible-integer-after-at-most-k-adjacent-swaps-on-digits
Hard
156 Greedy https://leetcode.com/problems/maximum-ice-cream-bars Medium
157 Greedy https://leetcode.com/problems/maximum-binary-string-after-change Medium
158 Greedy https://leetcode.com/problems/eliminate-maximum-number-of-monsters Medium
159 Greedy https://leetcode.com/problems/sum-game Medium
160 Greedy https://leetcode.com/problems/largest-values-from-labels Medium
161 Greedy https://leetcode.com/problems/find-servers-that-handled-most-number-of-requests Hard
162 Greedy https://leetcode.com/problems/minimum-time-to-type-word-using-special-typewriterEasy
163 Greedy https://leetcode.com/problems/decrease-elements-to-make-array-zigzag Medium
164 Greedy https://leetcode.com/problems/minimum-number-of-swaps-to-make-the-binary-string-alternating
Medium
165 Greedy https://leetcode.com/problems/merge-triplets-to-form-target-triplet Medium
166 Greedy https://leetcode.com/problems/maximum-matrix-sum Medium
167 Greedy https://leetcode.com/problems/two-furthest-houses-with-different-colors Easy
168 Greedy https://leetcode.com/problems/minimum-number-of-buckets-required-to-collect-rainwater-from-houses
Medium
169 Greedy https://leetcode.com/problems/array-with-elements-not-equal-to-average-of-neighbors
Medium
170 Greedy https://leetcode.com/problems/check-if-a-parentheses-string-can-be-valid Medium
171 Greedy https://leetcode.com/problems/maximum-value-after-insertion Medium
172 Greedy https://leetcode.com/problems/removing-minimum-and-maximum-from-array Medium
173 Greedy https://leetcode.com/problems/building-boxes Hard
174 Greedy https://leetcode.com/problems/minimum-cost-homecoming-of-a-robot-in-a-grid Medium
175 Greedy https://leetcode.com/problems/add-minimum-number-of-rungs Medium
176 Greedy https://leetcode.com/problems/latest-time-by-replacing-hidden-digits Easy
177 Greedy https://leetcode.com/problems/form-array-by-concatenating-subarrays-of-another-array
Medium
178 Greedy https://leetcode.com/problems/smallest-k-length-subsequence-with-occurrences-of-a-letter
Hard
179 Greedy https://leetcode.com/problems/previous-permutation-with-one-swap Medium
180 Greedy https://leetcode.com/problems/maximum-number-of-tasks-you-can-assign Hard
181 Greedy https://leetcode.com/problems/maximum-element-after-decreasing-and-rearranging Medium
182 Greedy https://leetcode.com/problems/remove-colored-pieces-if-both-neighbors-are-the-same-color
Medium
183 Greedy https://leetcode.com/problems/minimum-moves-to-convert-string Easy
184 Greedy https://leetcode.com/problems/longest-subsequence-repeated-k-times Hard
185 Greedy https://leetcode.com/problems/max-difference-you-can-get-from-changing-an-integer
Medium
186 Greedy https://leetcode.com/problems/minimum-elements-to-add-to-form-a-given-sum Medium
187 Greedy https://leetcode.com/problems/largest-number-after-mutating-substring Medium
188 Greedy https://leetcode.com/problems/minimum-number-of-people-to-teach Medium
189 Greedy https://leetcode.com/problems/stone-game-ix Medium
190 Greedy https://leetcode.com/problems/minimum-non-zero-product-of-the-array-elementsMedium
 Crack The Coding Interview - Dinesh Varyani
https://www.youtube.com/user/hubberspot?sub_confirmation=1

# Topic Question Difficulty

1 Depth-First Search https://leetcode.com/problems/number-of-islands Medium

2 Depth-First Search https://leetcode.com/problems/validate-binary-search-tree Medium
3 Depth-First Search https://leetcode.com/problems/lowest-common-ancestor-of-a-binary-tree Medium
4 Depth-First Search https://leetcode.com/problems/symmetric-tree Easy
5 Depth-First Search https://leetcode.com/problems/course-schedule Medium
6 Depth-First Search https://leetcode.com/problems/binary-tree-maximum-path-sum Hard
7 Depth-First Search https://leetcode.com/problems/invert-binary-tree Easy
8 Depth-First Search https://leetcode.com/problems/path-sum-iii Medium
9 Depth-First Search https://leetcode.com/problems/diameter-of-binary-tree Easy
10 Depth-First Search https://leetcode.com/problems/binary-tree-inorder-traversal Easy
11 Depth-First Search https://leetcode.com/problems/flatten-binary-tree-to-linked-list Medium
12 Depth-First Search https://leetcode.com/problems/course-schedule-ii Medium
13 Depth-First Search https://leetcode.com/problems/merge-two-binary-trees Easy
14 Depth-First Search https://leetcode.com/problems/serialize-and-deserialize-binary-tree Hard
15 Depth-First Search https://leetcode.com/problems/house-robber-iii Medium
16 Depth-First Search https://leetcode.com/problems/binary-tree-right-side-view Medium
17 Depth-First Search https://leetcode.com/problems/maximum-depth-of-binary-tree Easy
18 Depth-First Search https://leetcode.com/problems/populating-next-right-pointers-in-each-node Medium
19 Depth-First Search https://leetcode.com/problems/kth-smallest-element-in-a-bst Medium
20 Depth-First Search https://leetcode.com/problems/all-nodes-distance-k-in-binary-tree Medium
21 Depth-First Search https://leetcode.com/problems/max-area-of-island Medium
22 Depth-First Search https://leetcode.com/problems/balanced-binary-tree Easy
23 Depth-First Search https://leetcode.com/problems/minimum-height-trees Medium
24 Depth-First Search https://leetcode.com/problems/same-tree Easy
25 Depth-First Search https://leetcode.com/problems/lowest-common-ancestor-of-a-binary-search-tree Easy
26 Depth-First Search https://leetcode.com/problems/longest-increasing-path-in-a-matrix Hard
27 Depth-First Search https://leetcode.com/problems/path-sum Easy
28 Depth-First Search https://leetcode.com/problems/subtree-of-another-tree Easy
29 Depth-First Search https://leetcode.com/problems/evaluate-division Medium
30 Depth-First Search https://leetcode.com/problems/clone-graph Medium
31 Depth-First Search https://leetcode.com/problems/number-of-provinces Medium
32 Depth-First Search https://leetcode.com/problems/cheapest-flights-within-k-stops Medium
33 Depth-First Search https://leetcode.com/problems/surrounded-regions Medium
34 Depth-First Search https://leetcode.com/problems/count-complete-tree-nodes Medium
35 Depth-First Search https://leetcode.com/problems/path-sum-ii Medium
36 Depth-First Search https://leetcode.com/problems/island-perimeter Easy
37 Depth-First Search https://leetcode.com/problems/design-add-and-search-words-data-structure Medium
38 Depth-First Search https://leetcode.com/problems/accounts-merge Medium
39 Depth-First Search https://leetcode.com/problems/sum-root-to-leaf-numbers Medium
40 Depth-First Search https://leetcode.com/problems/recover-binary-search-tree Medium
41 Depth-First Search https://leetcode.com/problems/is-graph-bipartite Medium
42 Depth-First Search https://leetcode.com/problems/range-sum-of-bst Easy
43 Depth-First Search https://leetcode.com/problems/binary-tree-postorder-traversal Easy
44 Depth-First Search https://leetcode.com/problems/reconstruct-itinerary Hard
45 Depth-First Search https://leetcode.com/problems/network-delay-time Medium
46 Depth-First Search https://leetcode.com/problems/binary-tree-paths Easy
47 Depth-First Search https://leetcode.com/problems/minimum-depth-of-binary-tree Easy
48 Depth-First Search https://leetcode.com/problems/binary-tree-preorder-traversal Easy
49 Depth-First Search https://leetcode.com/problems/all-paths-from-source-to-target Medium
50 Depth-First Search https://leetcode.com/problems/trim-a-binary-search-tree Medium
51 Depth-First Search https://leetcode.com/problems/flatten-a-multilevel-doubly-linked-list Medium
52 Depth-First Search https://leetcode.com/problems/populating-next-right-pointers-in-each-node-ii Medium
53 Depth-First Search https://leetcode.com/problems/distribute-coins-in-binary-tree Medium
54 Depth-First Search https://leetcode.com/problems/critical-connections-in-a-network Hard
55 Depth-First Search https://leetcode.com/problems/redundant-connection Medium
56 Depth-First Search https://leetcode.com/problems/flood-fill Easy
57 Depth-First Search https://leetcode.com/problems/maximum-width-of-binary-tree Medium
58 Depth-First Search https://leetcode.com/problems/two-sum-iv-input-is-a-bst Easy
59 Depth-First Search https://leetcode.com/problems/convert-bst-to-greater-tree Medium
60 Depth-First Search https://leetcode.com/problems/pacific-atlantic-water-flow Medium
61 Depth-First Search https://leetcode.com/problems/sum-of-left-leaves Easy
 62 Depth-First Search https://leetcode.com/problems/flatten-nested-list-iterator Medium
63 Depth-First Search https://leetcode.com/problems/longest-univalue-path Medium
64 Depth-First Search https://leetcode.com/problems/find-duplicate-subtrees Medium
65 Depth-First Search https://leetcode.com/problems/average-of-levels-in-binary-tree Easy
66 Depth-First Search https://leetcode.com/problems/keys-and-rooms Medium
67 Depth-First Search https://leetcode.com/problems/delete-nodes-and-return-forest Medium
68 Depth-First Search https://leetcode.com/problems/vertical-order-traversal-of-a-binary-tree Hard
69 Depth-First Search https://leetcode.com/problems/serialize-and-deserialize-bst Medium
70 Depth-First Search https://leetcode.com/problems/cousins-in-binary-tree Easy
71 Depth-First Search https://leetcode.com/problems/binary-tree-cameras Hard
72 Depth-First Search https://leetcode.com/problems/jump-game-iii Medium
73 Depth-First Search https://leetcode.com/problems/sum-of-distances-in-tree Hard
74 Depth-First Search https://leetcode.com/problems/binary-tree-pruning Medium
75 Depth-First Search https://leetcode.com/problems/binary-search-tree-to-greater-sum-tree Medium
76 Depth-First Search https://leetcode.com/problems/most-stones-removed-with-same-row-or-column Medium
77 Depth-First Search https://leetcode.com/problems/maximum-difference-between-node-and-ancestorMedium
78 Depth-First Search https://leetcode.com/problems/deepest-leaves-sum Medium
79 Depth-First Search https://leetcode.com/problems/shortest-bridge Medium
80 Depth-First Search https://leetcode.com/problems/increasing-order-search-tree Easy
81 Depth-First Search https://leetcode.com/problems/possible-bipartition Medium
82 Depth-First Search https://leetcode.com/problems/making-a-large-island Hard
83 Depth-First Search https://leetcode.com/problems/count-good-nodes-in-binary-tree Medium
84 Depth-First Search https://leetcode.com/problems/find-mode-in-binary-search-tree Easy
85 Depth-First Search https://leetcode.com/problems/find-bottom-left-tree-value Medium
86 Depth-First Search https://leetcode.com/problems/regions-cut-by-slashes Medium
87 Depth-First Search https://leetcode.com/problems/path-with-minimum-effort Medium
88 Depth-First Search https://leetcode.com/problems/maximum-depth-of-n-ary-tree Easy
89 Depth-First Search https://leetcode.com/problems/find-largest-value-in-each-tree-row Medium
90 Depth-First Search https://leetcode.com/problems/array-nesting Medium
91 Depth-First Search https://leetcode.com/problems/minimum-absolute-difference-in-bst Easy
92 Depth-First Search https://leetcode.com/problems/smallest-subtree-with-all-the-deepest-nodes Medium
93 Depth-First Search https://leetcode.com/problems/sum-of-root-to-leaf-binary-numbers Easy
94 Depth-First Search https://leetcode.com/problems/find-eventual-safe-states Medium
95 Depth-First Search https://leetcode.com/problems/concatenated-words Hard
96 Depth-First Search https://leetcode.com/problems/swim-in-rising-water Hard
97 Depth-First Search https://leetcode.com/problems/number-of-operations-to-make-network-connected Medium
98 Depth-First Search https://leetcode.com/problems/leaf-similar-trees Easy
99 Depth-First Search https://leetcode.com/problems/sum-of-nodes-with-even-valued-grandparent Medium
100 Depth-First Search https://leetcode.com/problems/binary-tree-tilt Easy
101 Depth-First Search https://leetcode.com/problems/couples-holding-hands Hard
102 Depth-First Search https://leetcode.com/problems/n-ary-tree-preorder-traversal Easy
103 Depth-First Search https://leetcode.com/problems/flip-equivalent-binary-trees Medium
104 Depth-First Search https://leetcode.com/problems/balance-a-binary-search-tree Medium
105 Depth-First Search https://leetcode.com/problems/redundant-connection-ii Hard
106 Depth-First Search https://leetcode.com/problems/minimum-distance-between-bst-nodes Easy
107 Depth-First Search https://leetcode.com/problems/employee-importance Medium
108 Depth-First Search https://leetcode.com/problems/n-ary-tree-postorder-traversal Easy
109 Depth-First Search https://leetcode.com/problems/number-of-closed-islands Medium
110 Depth-First Search https://leetcode.com/problems/all-elements-in-two-binary-search-trees Medium
111 Depth-First Search https://leetcode.com/problems/time-needed-to-inform-all-employees Medium
112 Depth-First Search https://leetcode.com/problems/battleships-in-a-board Medium
113 Depth-First Search https://leetcode.com/problems/most-frequent-subtree-sum Medium
114 Depth-First Search https://leetcode.com/problems/smallest-string-with-swaps Medium
115 Depth-First Search https://leetcode.com/problems/construct-string-from-binary-tree Easy
116 Depth-First Search https://leetcode.com/problems/minesweeper Medium
117 Depth-First Search https://leetcode.com/problems/delete-leaves-with-a-given-value Medium
118 Depth-First Search https://leetcode.com/problems/linked-list-in-binary-tree Medium
119 Depth-First Search https://leetcode.com/problems/reorder-routes-to-make-all-paths-lead-to-the-city-zero
Medium
120 Depth-First Search https://leetcode.com/problems/add-one-row-to-tree Medium
121 Depth-First Search https://leetcode.com/problems/univalued-binary-tree Easy
122 Depth-First Search https://leetcode.com/problems/maximum-product-of-splitted-binary-tree Medium
123 Depth-First Search https://leetcode.com/problems/second-minimum-node-in-a-binary-tree Easy
124 Depth-First Search https://leetcode.com/problems/lexicographical-numbers Medium
125 Depth-First Search https://leetcode.com/problems/lowest-common-ancestor-of-deepest-leaves Medium
126 Depth-First Search https://leetcode.com/problems/number-of-good-leaf-nodes-pairs Medium
127 Depth-First Search https://leetcode.com/problems/smallest-string-starting-from-leaf Medium
128 Depth-First Search https://leetcode.com/problems/recover-a-tree-from-preorder-traversal Hard
129 Depth-First Search https://leetcode.com/problems/longest-absolute-file-path Medium
130 Depth-First Search https://leetcode.com/problems/longest-zigzag-path-in-a-binary-tree Medium
131 Depth-First Search https://leetcode.com/problems/pseudo-palindromic-paths-in-a-binary-tree Medium
132 Depth-First Search https://leetcode.com/problems/binary-tree-coloring-game Medium
133 Depth-First Search https://leetcode.com/problems/number-of-enclaves Medium
134 Depth-First Search https://leetcode.com/problems/maximum-sum-bst-in-binary-tree Hard
135 Depth-First Search https://leetcode.com/problems/minimum-time-to-collect-all-apples-in-a-tree Medium
136 Depth-First Search https://leetcode.com/problems/kth-ancestor-of-a-tree-node Hard
137 Depth-First Search https://leetcode.com/problems/count-servers-that-communicate Medium
138 Depth-First Search https://leetcode.com/problems/flower-planting-with-no-adjacent Medium
139 Depth-First Search https://leetcode.com/problems/similar-string-groups Hard
140 Depth-First Search https://leetcode.com/problems/flip-binary-tree-to-match-preorder-traversal Medium
141 Depth-First Search https://leetcode.com/problems/validate-binary-tree-nodes Medium
142 Depth-First Search https://leetcode.com/problems/course-schedule-iv Medium
143 Depth-First Search https://leetcode.com/problems/freedom-trail Hard
144 Depth-First Search https://leetcode.com/problems/find-a-corresponding-node-of-a-binary-tree-in-a-clone-of-that-tree
Medium
145 Depth-First Search https://leetcode.com/problems/water-and-jug-problem Medium
146 Depth-First Search https://leetcode.com/problems/where-will-the-ball-fall Medium
147 Depth-First Search https://leetcode.com/problems/count-sub-islands Medium
148 Depth-First Search https://leetcode.com/problems/minimize-malware-spread Hard
149 Depth-First Search https://leetcode.com/problems/sort-items-by-groups-respecting-dependencies Hard
150 Depth-First Search https://leetcode.com/problems/loud-and-rich Medium
151 Depth-First Search https://leetcode.com/problems/find-if-path-exists-in-graph Easy
152 Depth-First Search https://leetcode.com/problems/find-elements-in-a-contaminated-binary-tree Medium
153 Depth-First Search https://leetcode.com/problems/minimize-hamming-distance-after-swap-operations Medium
154 Depth-First Search https://leetcode.com/problems/check-if-there-is-a-valid-path-in-a-grid Medium
155 Depth-First Search https://leetcode.com/problems/detect-cycles-in-2d-grid Medium
156 Depth-First Search https://leetcode.com/problems/pyramid-transition-matrix Medium
157 Depth-First Search https://leetcode.com/problems/escape-a-large-maze Hard
158 Depth-First Search https://leetcode.com/problems/minimize-malware-spread-ii Hard
159 Depth-First Search https://leetcode.com/problems/last-day-where-you-can-still-cross Hard
160 Depth-First Search https://leetcode.com/problems/insufficient-nodes-in-root-to-leaf-paths Medium
161 Depth-First Search https://leetcode.com/problems/frog-position-after-t-seconds Hard
162 Depth-First Search https://leetcode.com/problems/mini-parser Medium
163 Depth-First Search https://leetcode.com/problems/step-by-step-directions-from-a-binary-tree-node-to-another
Medium
164 Depth-First Search https://leetcode.com/problems/number-of-nodes-in-the-sub-tree-with-the-same-label
Medium
165 Depth-First Search https://leetcode.com/problems/coloring-a-border Medium
166 Depth-First Search https://leetcode.com/problems/minimum-number-of-days-to-disconnect-island Hard
167 Depth-First Search https://leetcode.com/problems/find-all-people-with-secret Hard
168 Depth-First Search https://leetcode.com/problems/count-nodes-with-the-highest-score Medium
169 Depth-First Search https://leetcode.com/problems/find-all-groups-of-farmland Medium
170 Depth-First Search https://leetcode.com/problems/smallest-missing-genetic-value-in-each-subtree Hard
171 Depth-First Search https://leetcode.com/problems/tree-of-coprimes Hard
172 Depth-First Search https://leetcode.com/problems/contain-virus Hard
173 Depth-First Search https://leetcode.com/problems/detonate-the-maximum-bombs Medium
174 Depth-First Search https://leetcode.com/problems/valid-arrangement-of-pairs Hard
175 Depth-First Search https://leetcode.com/problems/merge-bsts-to-create-single-bst Hard
176 Depth-First Search https://leetcode.com/problems/throne-inheritance Medium
177 Depth-First Search https://leetcode.com/problems/cracking-the-safe Hard
178 Depth-First Search https://leetcode.com/problems/print-binary-tree Medium
179 Depth-First Search https://leetcode.com/problems/bulb-switcher-ii Medium
 Crack The Coding Interview - Dinesh Varyani
https://www.youtube.com/user/hubberspot?sub_confirmation=1

# Topic Question Difficulty

1 Breadth-First Search https://leetcode.com/problems/number-of-islands Medium

2 Breadth-First Search https://leetcode.com/problems/coin-change Medium
3 Breadth-First Search https://leetcode.com/problems/symmetric-tree Easy
4 Breadth-First Search https://leetcode.com/problems/course-schedule Medium
5 Breadth-First Search https://leetcode.com/problems/invert-binary-tree Easy
6 Breadth-First Search https://leetcode.com/problems/binary-tree-level-order-traversal Medium
7 Breadth-First Search https://leetcode.com/problems/word-ladder Hard
8 Breadth-First Search https://leetcode.com/problems/perfect-squares Medium
9 Breadth-First Search https://leetcode.com/problems/course-schedule-ii Medium
10 Breadth-First Search https://leetcode.com/problems/merge-two-binary-trees Easy
11 Breadth-First Search https://leetcode.com/problems/serialize-and-deserialize-binary-tree Hard
12 Breadth-First Search https://leetcode.com/problems/binary-tree-right-side-view Medium
13 Breadth-First Search https://leetcode.com/problems/maximum-depth-of-binary-tree Easy
14 Breadth-First Search https://leetcode.com/problems/rotting-oranges Medium
15 Breadth-First Search https://leetcode.com/problems/populating-next-right-pointers-in-each-node Medium
16 Breadth-First Search https://leetcode.com/problems/all-nodes-distance-k-in-binary-tree Medium
17 Breadth-First Search https://leetcode.com/problems/max-area-of-island Medium
18 Breadth-First Search https://leetcode.com/problems/binary-tree-zigzag-level-order-traversal Medium
19 Breadth-First Search https://leetcode.com/problems/minimum-height-trees Medium
20 Breadth-First Search https://leetcode.com/problems/same-tree Easy
21 Breadth-First Search https://leetcode.com/problems/longest-increasing-path-in-a-matrix Hard
22 Breadth-First Search https://leetcode.com/problems/evaluate-division Medium
23 Breadth-First Search https://leetcode.com/problems/clone-graph Medium
24 Breadth-First Search https://leetcode.com/problems/number-of-provinces Medium
25 Breadth-First Search https://leetcode.com/problems/cheapest-flights-within-k-stops Medium
26 Breadth-First Search https://leetcode.com/problems/surrounded-regions Medium
27 Breadth-First Search https://leetcode.com/problems/remove-invalid-parentheses Hard
28 Breadth-First Search https://leetcode.com/problems/island-perimeter Easy
29 Breadth-First Search https://leetcode.com/problems/01-matrix Medium
30 Breadth-First Search https://leetcode.com/problems/accounts-merge Medium
31 Breadth-First Search https://leetcode.com/problems/is-graph-bipartite Medium
32 Breadth-First Search https://leetcode.com/problems/network-delay-time Medium
33 Breadth-First Search https://leetcode.com/problems/minimum-depth-of-binary-tree Easy
34 Breadth-First Search https://leetcode.com/problems/all-paths-from-source-to-target Medium
35 Breadth-First Search https://leetcode.com/problems/word-ladder-ii Hard
36 Breadth-First Search https://leetcode.com/problems/populating-next-right-pointers-in-each-node-ii Medium
37 Breadth-First Search https://leetcode.com/problems/redundant-connection Medium
38 Breadth-First Search https://leetcode.com/problems/flood-fill Easy
39 Breadth-First Search https://leetcode.com/problems/maximum-width-of-binary-tree Medium
40 Breadth-First Search https://leetcode.com/problems/two-sum-iv-input-is-a-bst Easy
41 Breadth-First Search https://leetcode.com/problems/pacific-atlantic-water-flow Medium
42 Breadth-First Search https://leetcode.com/problems/sum-of-left-leaves Easy
43 Breadth-First Search https://leetcode.com/problems/binary-tree-level-order-traversal-ii Medium
44 Breadth-First Search https://leetcode.com/problems/find-duplicate-subtrees Medium
45 Breadth-First Search https://leetcode.com/problems/average-of-levels-in-binary-tree Easy
46 Breadth-First Search https://leetcode.com/problems/keys-and-rooms Medium
47 Breadth-First Search https://leetcode.com/problems/vertical-order-traversal-of-a-binary-tree Hard
48 Breadth-First Search https://leetcode.com/problems/open-the-lock Medium
49 Breadth-First Search https://leetcode.com/problems/serialize-and-deserialize-bst Medium
50 Breadth-First Search https://leetcode.com/problems/trapping-rain-water-ii Hard
51 Breadth-First Search https://leetcode.com/problems/cousins-in-binary-tree Easy
52 Breadth-First Search https://leetcode.com/problems/jump-game-iii Medium
53 Breadth-First Search https://leetcode.com/problems/deepest-leaves-sum Medium
54 Breadth-First Search https://leetcode.com/problems/shortest-bridge Medium
55 Breadth-First Search https://leetcode.com/problems/possible-bipartition Medium
56 Breadth-First Search https://leetcode.com/problems/making-a-large-island Hard
57 Breadth-First Search https://leetcode.com/problems/shortest-path-in-binary-matrix Medium
58 Breadth-First Search https://leetcode.com/problems/count-good-nodes-in-binary-tree Medium
59 Breadth-First Search https://leetcode.com/problems/find-bottom-left-tree-value Medium
60 Breadth-First Search https://leetcode.com/problems/regions-cut-by-slashes Medium
61 Breadth-First Search https://leetcode.com/problems/path-with-minimum-effort Medium
 62 Breadth-First Search https://leetcode.com/problems/maximum-depth-of-n-ary-tree Easy
63 Breadth-First Search https://leetcode.com/problems/find-largest-value-in-each-tree-row Medium
64 Breadth-First Search https://leetcode.com/problems/minimum-absolute-difference-in-bst Easy
65 Breadth-First Search https://leetcode.com/problems/smallest-subtree-with-all-the-deepest-nodes Medium
66 Breadth-First Search https://leetcode.com/problems/shortest-path-in-a-grid-with-obstacles-eliminationHard
67 Breadth-First Search https://leetcode.com/problems/check-completeness-of-a-binary-tree Medium
68 Breadth-First Search https://leetcode.com/problems/find-eventual-safe-states Medium
69 Breadth-First Search https://leetcode.com/problems/bus-routes Hard
70 Breadth-First Search https://leetcode.com/problems/swim-in-rising-water Hard
71 Breadth-First Search https://leetcode.com/problems/number-of-operations-to-make-network-connected Medium
72 Breadth-First Search https://leetcode.com/problems/n-ary-tree-level-order-traversal Medium
73 Breadth-First Search https://leetcode.com/problems/sum-of-nodes-with-even-valued-grandparent Medium
74 Breadth-First Search https://leetcode.com/problems/couples-holding-hands Hard
75 Breadth-First Search https://leetcode.com/problems/redundant-connection-ii Hard
76 Breadth-First Search https://leetcode.com/problems/minimum-distance-between-bst-nodes Easy
77 Breadth-First Search https://leetcode.com/problems/employee-importance Medium
78 Breadth-First Search https://leetcode.com/problems/number-of-closed-islands Medium
79 Breadth-First Search https://leetcode.com/problems/as-far-from-land-as-possible Medium
80 Breadth-First Search https://leetcode.com/problems/time-needed-to-inform-all-employees Medium
81 Breadth-First Search https://leetcode.com/problems/sliding-puzzle Hard
82 Breadth-First Search https://leetcode.com/problems/smallest-string-with-swaps Medium
83 Breadth-First Search https://leetcode.com/problems/shortest-path-visiting-all-nodes Hard
84 Breadth-First Search https://leetcode.com/problems/minesweeper Medium
85 Breadth-First Search https://leetcode.com/problems/maximum-level-sum-of-a-binary-tree Medium
86 Breadth-First Search https://leetcode.com/problems/delete-leaves-with-a-given-value Medium
87 Breadth-First Search https://leetcode.com/problems/linked-list-in-binary-tree Medium
88 Breadth-First Search https://leetcode.com/problems/reorder-routes-to-make-all-paths-lead-to-the-city-zero
Medium
89 Breadth-First Search https://leetcode.com/problems/add-one-row-to-tree Medium
90 Breadth-First Search https://leetcode.com/problems/univalued-binary-tree Easy
91 Breadth-First Search https://leetcode.com/problems/lowest-common-ancestor-of-deepest-leaves Medium
92 Breadth-First Search https://leetcode.com/problems/shortest-path-with-alternating-colors Medium
93 Breadth-First Search https://leetcode.com/problems/jump-game-iv Hard
94 Breadth-First Search https://leetcode.com/problems/minimum-cost-to-make-at-least-one-valid-path-in-a-grid
Hard
95 Breadth-First Search https://leetcode.com/problems/pseudo-palindromic-paths-in-a-binary-tree Medium
96 Breadth-First Search https://leetcode.com/problems/number-of-enclaves Medium
97 Breadth-First Search https://leetcode.com/problems/minimum-time-to-collect-all-apples-in-a-tree Medium
98 Breadth-First Search https://leetcode.com/problems/kth-ancestor-of-a-tree-node Hard
99 Breadth-First Search https://leetcode.com/problems/cut-off-trees-for-golf-event Hard
100 Breadth-First Search https://leetcode.com/problems/numbers-with-same-consecutive-differences Medium
101 Breadth-First Search https://leetcode.com/problems/count-servers-that-communicate Medium
102 Breadth-First Search https://leetcode.com/problems/k-similar-strings Hard
103 Breadth-First Search https://leetcode.com/problems/flower-planting-with-no-adjacent Medium
104 Breadth-First Search https://leetcode.com/problems/minimum-genetic-mutation Medium
105 Breadth-First Search https://leetcode.com/problems/shortest-path-to-get-all-keys Hard
106 Breadth-First Search https://leetcode.com/problems/similar-string-groups Hard
107 Breadth-First Search https://leetcode.com/problems/complete-binary-tree-inserter Medium
108 Breadth-First Search https://leetcode.com/problems/validate-binary-tree-nodes Medium
109 Breadth-First Search https://leetcode.com/problems/course-schedule-iv Medium
110 Breadth-First Search https://leetcode.com/problems/freedom-trail Hard
111 Breadth-First Search https://leetcode.com/problems/find-a-corresponding-node-of-a-binary-tree-in-a-clone-of-that-tree
Medium
112 Breadth-First Search https://leetcode.com/problems/water-and-jug-problem Medium
113 Breadth-First Search https://leetcode.com/problems/minimum-jumps-to-reach-home Medium
114 Breadth-First Search https://leetcode.com/problems/cat-and-mouse Hard
115 Breadth-First Search https://leetcode.com/problems/count-sub-islands Medium
116 Breadth-First Search https://leetcode.com/problems/minimum-moves-to-move-a-box-to-their-target-location
Hard
117 Breadth-First Search https://leetcode.com/problems/minimize-malware-spread Hard
118 Breadth-First Search https://leetcode.com/problems/sort-items-by-groups-respecting-dependencies Hard
119 Breadth-First Search https://leetcode.com/problems/even-odd-tree Medium
120 Breadth-First Search https://leetcode.com/problems/find-if-path-exists-in-graph Easy
121 Breadth-First Search https://leetcode.com/problems/find-elements-in-a-contaminated-binary-tree Medium
122 Breadth-First Search https://leetcode.com/problems/check-if-there-is-a-valid-path-in-a-grid Medium
123 Breadth-First Search https://leetcode.com/problems/detect-cycles-in-2d-grid Medium
124 Breadth-First Search https://leetcode.com/problems/minimum-number-of-flips-to-convert-binary-matrix-to-zero-matrix
Hard
125 Breadth-First Search https://leetcode.com/problems/pyramid-transition-matrix Medium
126 Breadth-First Search https://leetcode.com/problems/map-of-highest-peak Medium
127 Breadth-First Search https://leetcode.com/problems/snakes-and-ladders Medium
128 Breadth-First Search https://leetcode.com/problems/escape-a-large-maze Hard
129 Breadth-First Search https://leetcode.com/problems/minimize-malware-spread-ii Hard
130 Breadth-First Search https://leetcode.com/problems/last-day-where-you-can-still-cross Hard
131 Breadth-First Search https://leetcode.com/problems/frog-position-after-t-seconds Hard
132 Breadth-First Search https://leetcode.com/problems/number-of-nodes-in-the-sub-tree-with-the-same-label
Medium
133 Breadth-First Search https://leetcode.com/problems/brace-expansion-ii Hard
134 Breadth-First Search https://leetcode.com/problems/coloring-a-border Medium
135 Breadth-First Search https://leetcode.com/problems/minimum-number-of-days-to-disconnect-island Hard
136 Breadth-First Search https://leetcode.com/problems/zuma-game Hard
137 Breadth-First Search https://leetcode.com/problems/find-all-people-with-secret Hard
138 Breadth-First Search https://leetcode.com/problems/nearest-exit-from-entrance-in-maze Medium
139 Breadth-First Search https://leetcode.com/problems/minimum-operations-to-convert-number Medium
140 Breadth-First Search https://leetcode.com/problems/second-minimum-time-to-reach-destination Hard
141 Breadth-First Search https://leetcode.com/problems/find-all-groups-of-farmland Medium
142 Breadth-First Search https://leetcode.com/problems/tree-of-coprimes Hard
143 Breadth-First Search https://leetcode.com/problems/lexicographically-smallest-string-after-applying-operations
Medium
144 Breadth-First Search https://leetcode.com/problems/contain-virus Hard
145 Breadth-First Search https://leetcode.com/problems/get-watched-videos-by-your-friends Medium
146 Breadth-First Search https://leetcode.com/problems/detonate-the-maximum-bombs Medium
147 Breadth-First Search https://leetcode.com/problems/the-time-when-the-network-becomes-idle Medium
148 Breadth-First Search https://leetcode.com/problems/minimum-moves-to-reach-target-with-rotations Hard
149 Breadth-First Search https://leetcode.com/problems/operations-on-tree Medium
150 Breadth-First Search https://leetcode.com/problems/maximum-candies-you-can-get-from-boxes Hard
151 Breadth-First Search https://leetcode.com/problems/cat-and-mouse-ii Hard
152 Breadth-First Search https://leetcode.com/problems/print-binary-tree Medium
153 Breadth-First Search https://leetcode.com/problems/bulb-switcher-ii Medium
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# Topic Question Difficulty

1 Binary Search https://leetcode.com/problems/median-of-two-sorted-arrays Hard

2 Binary Search https://leetcode.com/problems/search-in-rotated-sorted-array Medium
3 Binary Search https://leetcode.com/problems/find-the-duplicate-number Medium
4 Binary Search https://leetcode.com/problems/longest-increasing-subsequence Medium
5 Binary Search https://leetcode.com/problems/find-first-and-last-position-of-element-in-sorted-array
Medium
6 Binary Search https://leetcode.com/problems/search-a-2d-matrix-ii Medium
7 Binary Search https://leetcode.com/problems/search-insert-position Easy
8 Binary Search https://leetcode.com/problems/search-a-2d-matrix Medium
9 Binary Search https://leetcode.com/problems/find-minimum-in-rotated-sorted-array Medium
10 Binary Search https://leetcode.com/problems/minimum-size-subarray-sum Medium
11 Binary Search https://leetcode.com/problems/kth-smallest-element-in-a-sorted-matrix Medium
12 Binary Search https://leetcode.com/problems/count-of-smaller-numbers-after-self Hard
13 Binary Search https://leetcode.com/problems/find-peak-element Medium
14 Binary Search https://leetcode.com/problems/single-element-in-a-sorted-array Medium
15 Binary Search https://leetcode.com/problems/count-complete-tree-nodes Medium
16 Binary Search https://leetcode.com/problems/two-sum-ii-input-array-is-sorted Easy
17 Binary Search https://leetcode.com/problems/split-array-largest-sum Hard
18 Binary Search https://leetcode.com/problems/first-bad-version Easy
19 Binary Search https://leetcode.com/problems/max-consecutive-ones-iii Medium
20 Binary Search https://leetcode.com/problems/intersection-of-two-arrays-ii Easy
21 Binary Search https://leetcode.com/problems/find-k-closest-elements Medium
22 Binary Search https://leetcode.com/problems/maximum-length-of-repeated-subarray Medium
23 Binary Search https://leetcode.com/problems/capacity-to-ship-packages-within-d-days Medium
24 Binary Search https://leetcode.com/problems/search-in-rotated-sorted-array-ii Medium
25 Binary Search https://leetcode.com/problems/sqrtx Easy
26 Binary Search https://leetcode.com/problems/binary-search Easy
27 Binary Search https://leetcode.com/problems/132-pattern Medium
28 Binary Search https://leetcode.com/problems/russian-doll-envelopes Hard
29 Binary Search https://leetcode.com/problems/maximum-profit-in-job-scheduling Hard
30 Binary Search https://leetcode.com/problems/shortest-subarray-with-sum-at-least-k Hard
31 Binary Search https://leetcode.com/problems/find-minimum-in-rotated-sorted-array-ii Hard
32 Binary Search https://leetcode.com/problems/koko-eating-bananas Medium
33 Binary Search https://leetcode.com/problems/reverse-pairs Hard
34 Binary Search https://leetcode.com/problems/intersection-of-two-arrays Easy
35 Binary Search https://leetcode.com/problems/valid-triangle-number Medium
36 Binary Search https://leetcode.com/problems/super-egg-drop Hard
37 Binary Search https://leetcode.com/problems/kth-missing-positive-number Easy
38 Binary Search https://leetcode.com/problems/peak-index-in-a-mountain-array Easy
39 Binary Search https://leetcode.com/problems/longest-arithmetic-subsequence Medium
40 Binary Search https://leetcode.com/problems/valid-perfect-square Easy
41 Binary Search https://leetcode.com/problems/arranging-coins Easy
42 Binary Search https://leetcode.com/problems/path-with-minimum-effort Medium
43 Binary Search https://leetcode.com/problems/max-sum-of-rectangle-no-larger-than-k Hard
44 Binary Search https://leetcode.com/problems/time-based-key-value-store Medium
45 Binary Search https://leetcode.com/problems/count-negative-numbers-in-a-sorted-matrix Easy
46 Binary Search https://leetcode.com/problems/find-k-th-smallest-pair-distance Hard
47 Binary Search https://leetcode.com/problems/swim-in-rising-water Hard
48 Binary Search https://leetcode.com/problems/k-diff-pairs-in-an-array Medium
49 Binary Search https://leetcode.com/problems/longest-duplicate-substring Hard
50 Binary Search https://leetcode.com/problems/kth-smallest-number-in-multiplication-table Hard
51 Binary Search https://leetcode.com/problems/count-of-range-sum Hard
52 Binary Search https://leetcode.com/problems/the-k-weakest-rows-in-a-matrix Easy
53 Binary Search https://leetcode.com/problems/minimum-number-of-days-to-make-m-bouquets Medium
54 Binary Search https://leetcode.com/problems/minimum-operations-to-reduce-x-to-zero Medium
55 Binary Search https://leetcode.com/problems/snapshot-array Medium
56 Binary Search https://leetcode.com/problems/find-smallest-letter-greater-than-target Easy
57 Binary Search https://leetcode.com/problems/heaters Medium
58 Binary Search https://leetcode.com/problems/sum-of-square-numbers Medium
59 Binary Search https://leetcode.com/problems/find-the-smallest-divisor-given-a-threshold Medium
60 Binary Search https://leetcode.com/problems/fair-candy-swap Easy
61 Binary Search https://leetcode.com/problems/find-two-non-overlapping-sub-arrays-each-with-target-sum
Medium
 62 Binary Search https://leetcode.com/problems/find-right-interval Medium
63 Binary Search https://leetcode.com/problems/numbers-at-most-n-given-digit-set Hard
64 Binary Search https://leetcode.com/problems/reach-a-number Medium
65 Binary Search https://leetcode.com/problems/find-in-mountain-array Hard
66 Binary Search https://leetcode.com/problems/magnetic-force-between-two-balls Medium
67 Binary Search https://leetcode.com/problems/nth-magical-number Hard
68 Binary Search https://leetcode.com/problems/number-of-subsequences-that-satisfy-the-given-sum-condition
Medium
69 Binary Search https://leetcode.com/problems/frequency-of-the-most-frequent-element Medium
70 Binary Search https://leetcode.com/problems/avoid-flood-in-the-city Medium
71 Binary Search https://leetcode.com/problems/shortest-subarray-to-be-removed-to-make-array-sorted
Medium
72 Binary Search https://leetcode.com/problems/kth-ancestor-of-a-tree-node Hard
73 Binary Search https://leetcode.com/problems/minimum-limit-of-balls-in-a-bag Medium
74 Binary Search https://leetcode.com/problems/find-the-kth-smallest-sum-of-a-matrix-with-sorted-rows
Hard
75 Binary Search https://leetcode.com/problems/most-profit-assigning-work Medium
76 Binary Search https://leetcode.com/problems/maximum-side-length-of-a-square-with-sum-less-than-or-equal-to-threshold
Medium
77 Binary Search https://leetcode.com/problems/k-th-smallest-prime-fraction Hard
78 Binary Search https://leetcode.com/problems/check-if-n-and-its-double-exist Easy
79 Binary Search https://leetcode.com/problems/sum-of-mutated-array-closest-to-target Medium
80 Binary Search https://leetcode.com/problems/ugly-number-iii Medium
81 Binary Search https://leetcode.com/problems/h-index-ii Medium
82 Binary Search https://leetcode.com/problems/ways-to-split-array-into-three-subarrays Medium
83 Binary Search https://leetcode.com/problems/online-election Medium
84 Binary Search https://leetcode.com/problems/nth-digit Medium
85 Binary Search https://leetcode.com/problems/sell-diminishing-valued-colored-balls Medium
86 Binary Search https://leetcode.com/problems/data-stream-as-disjoint-intervals Hard
87 Binary Search https://leetcode.com/problems/get-equal-substrings-within-budget Medium
88 Binary Search https://leetcode.com/problems/minimum-number-of-removals-to-make-mountain-array Hard
89 Binary Search https://leetcode.com/problems/make-array-strictly-increasing Hard
90 Binary Search https://leetcode.com/problems/random-pick-with-blacklist Hard
91 Binary Search https://leetcode.com/problems/special-array-with-x-elements-greater-than-or-equal-x
Easy
92 Binary Search https://leetcode.com/problems/guess-number-higher-or-lower Easy
93 Binary Search https://leetcode.com/problems/friends-of-appropriate-ages Medium
94 Binary Search https://leetcode.com/problems/find-a-peak-element-ii Medium
95 Binary Search https://leetcode.com/problems/range-sum-of-sorted-subarray-sums Medium
96 Binary Search https://leetcode.com/problems/maximum-number-of-removable-characters Medium
97 Binary Search https://leetcode.com/problems/maximum-score-of-a-good-subarray Hard
98 Binary Search https://leetcode.com/problems/compare-strings-by-frequency-of-the-smallest-character
Medium
99 Binary Search https://leetcode.com/problems/create-sorted-array-through-instructions Hard
100 Binary Search https://leetcode.com/problems/maximum-value-at-a-given-index-in-a-bounded-array Medium
101 Binary Search https://leetcode.com/problems/online-majority-element-in-subarray Hard
102 Binary Search https://leetcode.com/problems/find-latest-group-of-size-m Medium
103 Binary Search https://leetcode.com/problems/maximum-distance-between-a-pair-of-values Medium
104 Binary Search https://leetcode.com/problems/minimum-absolute-sum-difference Medium
105 Binary Search https://leetcode.com/problems/maximum-earnings-from-taxi Medium
106 Binary Search https://leetcode.com/problems/maximum-number-of-events-that-can-be-attended-ii Hard
107 Binary Search https://leetcode.com/problems/minimum-speed-to-arrive-on-time Medium
108 Binary Search https://leetcode.com/problems/minimum-operations-to-make-the-array-k-increasing Hard
109 Binary Search https://leetcode.com/problems/random-point-in-non-overlapping-rectangles Medium
110 Binary Search https://leetcode.com/problems/last-day-where-you-can-still-cross Hard
111 Binary Search https://leetcode.com/problems/minimum-operations-to-make-a-subsequence Hard
112 Binary Search https://leetcode.com/problems/find-the-longest-valid-obstacle-course-at-each-position
Hard
113 Binary Search https://leetcode.com/problems/find-positive-integer-solution-for-a-given-equationMedium
114 Binary Search https://leetcode.com/problems/minimum-interval-to-include-each-query Hard
115 Binary Search https://leetcode.com/problems/maximize-the-confusion-of-an-exam Medium
116 Binary Search https://leetcode.com/problems/minimum-number-of-operations-to-make-array-continuous
Hard
117 Binary Search https://leetcode.com/problems/partition-array-into-two-arrays-to-minimize-sum-difference
Hard
118 Binary Search https://leetcode.com/problems/two-best-non-overlapping-events Medium
119 Binary Search https://leetcode.com/problems/closest-room Hard
120 Binary Search https://leetcode.com/problems/random-pick-with-weight Medium
121 Binary Search https://leetcode.com/problems/preimage-size-of-factorial-zeroes-function Hard
122 Binary Search https://leetcode.com/problems/find-target-indices-after-sorting-array Easy
123 Binary Search https://leetcode.com/problems/range-frequency-queries Medium
124 Binary Search https://leetcode.com/problems/find-the-distance-value-between-two-arrays Easy
125 Binary Search https://leetcode.com/problems/sum-of-floored-pairs Hard
126 Binary Search https://leetcode.com/problems/minimized-maximum-of-products-distributed-to-any-store
Medium
127 Binary Search https://leetcode.com/problems/plates-between-candles Medium
128 Binary Search https://leetcode.com/problems/smallest-good-base Hard
129 Binary Search https://leetcode.com/problems/find-a-value-of-a-mysterious-function-closest-to-target
Hard
130 Binary Search https://leetcode.com/problems/longest-common-subpath Hard
131 Binary Search https://leetcode.com/problems/most-beautiful-item-for-each-query Medium
132 Binary Search https://leetcode.com/problems/minimum-space-wasted-from-packaging Hard
133 Binary Search https://leetcode.com/problems/maximum-fruits-harvested-after-at-most-k-steps Hard
134 Binary Search https://leetcode.com/problems/building-boxes Hard
135 Binary Search https://leetcode.com/problems/kth-smallest-product-of-two-sorted-arrays Hard
136 Binary Search https://leetcode.com/problems/count-pairs-of-nodes Hard
137 Binary Search https://leetcode.com/problems/find-the-student-that-will-replace-the-chalk Medium
138 Binary Search https://leetcode.com/problems/merge-bsts-to-create-single-bst Hard
139 Binary Search https://leetcode.com/problems/minimum-garden-perimeter-to-collect-enough-apples Medium
140 Binary Search https://leetcode.com/problems/maximum-number-of-tasks-you-can-assign Hard
141 Binary Search https://leetcode.com/problems/tweet-counts-per-frequency Medium
 Crack The Coding Interview - Dinesh Varyani
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# Topic Question Difficulty

1 Tree https://leetcode.com/problems/validate-binary-search-tree Medium

2 Tree https://leetcode.com/problems/lowest-common-ancestor-of-a-binary-tree Medium
3 Tree https://leetcode.com/problems/symmetric-tree Easy
4 Tree https://leetcode.com/problems/binary-tree-maximum-path-sum Hard
5 Tree https://leetcode.com/problems/construct-binary-tree-from-preorder-and-inorder-traversal
Medium
6 Tree https://leetcode.com/problems/invert-binary-tree Easy
7 Tree https://leetcode.com/problems/path-sum-iii Medium
8 Tree https://leetcode.com/problems/binary-tree-level-order-traversal Medium
9 Tree https://leetcode.com/problems/diameter-of-binary-tree Easy
10 Tree https://leetcode.com/problems/binary-tree-inorder-traversal Easy
11 Tree https://leetcode.com/problems/unique-binary-search-trees Medium
12 Tree https://leetcode.com/problems/flatten-binary-tree-to-linked-list Medium
13 Tree https://leetcode.com/problems/merge-two-binary-trees Easy
14 Tree https://leetcode.com/problems/serialize-and-deserialize-binary-tree Hard
15 Tree https://leetcode.com/problems/house-robber-iii Medium
16 Tree https://leetcode.com/problems/binary-tree-right-side-view Medium
17 Tree https://leetcode.com/problems/maximum-depth-of-binary-tree Easy
18 Tree https://leetcode.com/problems/convert-sorted-array-to-binary-search-tree Easy
19 Tree https://leetcode.com/problems/populating-next-right-pointers-in-each-node Medium
20 Tree https://leetcode.com/problems/kth-smallest-element-in-a-bst Medium
21 Tree https://leetcode.com/problems/all-nodes-distance-k-in-binary-tree Medium
22 Tree https://leetcode.com/problems/binary-tree-zigzag-level-order-traversal Medium
23 Tree https://leetcode.com/problems/balanced-binary-tree Easy
24 Tree https://leetcode.com/problems/same-tree Easy
25 Tree https://leetcode.com/problems/lowest-common-ancestor-of-a-binary-search-tree Easy
26 Tree https://leetcode.com/problems/binary-search-tree-iterator Medium
27 Tree https://leetcode.com/problems/path-sum Easy
28 Tree https://leetcode.com/problems/delete-node-in-a-bst Medium
29 Tree https://leetcode.com/problems/subtree-of-another-tree Easy
30 Tree https://leetcode.com/problems/unique-binary-search-trees-ii Medium
31 Tree https://leetcode.com/problems/count-complete-tree-nodes Medium
32 Tree https://leetcode.com/problems/path-sum-ii Medium
33 Tree https://leetcode.com/problems/convert-sorted-list-to-binary-search-tree Medium
34 Tree https://leetcode.com/problems/construct-binary-tree-from-inorder-and-postorder-traversal
Medium
35 Tree https://leetcode.com/problems/sum-root-to-leaf-numbers Medium
36 Tree https://leetcode.com/problems/recover-binary-search-tree Medium
37 Tree https://leetcode.com/problems/range-sum-of-bst Easy
38 Tree https://leetcode.com/problems/binary-tree-postorder-traversal Easy
39 Tree https://leetcode.com/problems/binary-tree-paths Easy
40 Tree https://leetcode.com/problems/minimum-depth-of-binary-tree Easy
41 Tree https://leetcode.com/problems/binary-tree-preorder-traversal Easy
42 Tree https://leetcode.com/problems/trim-a-binary-search-tree Medium
43 Tree https://leetcode.com/problems/populating-next-right-pointers-in-each-node-ii Medium
44 Tree https://leetcode.com/problems/maximum-binary-tree Medium
45 Tree https://leetcode.com/problems/distribute-coins-in-binary-tree Medium
46 Tree https://leetcode.com/problems/maximum-width-of-binary-tree Medium
47 Tree https://leetcode.com/problems/construct-binary-search-tree-from-preorder-traversal
Medium
48 Tree https://leetcode.com/problems/two-sum-iv-input-is-a-bst Easy
49 Tree https://leetcode.com/problems/convert-bst-to-greater-tree Medium
50 Tree https://leetcode.com/problems/sum-of-left-leaves Easy
51 Tree https://leetcode.com/problems/flatten-nested-list-iterator Medium
52 Tree https://leetcode.com/problems/longest-univalue-path Medium
53 Tree https://leetcode.com/problems/binary-tree-level-order-traversal-ii Medium
54 Tree https://leetcode.com/problems/find-duplicate-subtrees Medium
55 Tree https://leetcode.com/problems/average-of-levels-in-binary-tree Easy
56 Tree https://leetcode.com/problems/delete-nodes-and-return-forest Medium
57 Tree https://leetcode.com/problems/vertical-order-traversal-of-a-binary-tree Hard
58 Tree https://leetcode.com/problems/serialize-and-deserialize-bst Medium
59 Tree https://leetcode.com/problems/cousins-in-binary-tree Easy
60 Tree https://leetcode.com/problems/binary-tree-cameras Hard
61 Tree https://leetcode.com/problems/insert-into-a-binary-search-tree Medium
 62 Tree https://leetcode.com/problems/sum-of-distances-in-tree Hard
63 Tree https://leetcode.com/problems/search-in-a-binary-search-tree Easy
64 Tree https://leetcode.com/problems/all-possible-full-binary-trees Medium
65 Tree https://leetcode.com/problems/binary-tree-pruning Medium
66 Tree https://leetcode.com/problems/binary-search-tree-to-greater-sum-tree Medium
67 Tree https://leetcode.com/problems/maximum-difference-between-node-and-ancestorMedium
68 Tree https://leetcode.com/problems/deepest-leaves-sum Medium
69 Tree https://leetcode.com/problems/increasing-order-search-tree Easy
70 Tree https://leetcode.com/problems/count-good-nodes-in-binary-tree Medium
71 Tree https://leetcode.com/problems/find-mode-in-binary-search-tree Easy
72 Tree https://leetcode.com/problems/find-bottom-left-tree-value Medium
73 Tree https://leetcode.com/problems/kth-largest-element-in-a-stream Easy
74 Tree https://leetcode.com/problems/maximum-depth-of-n-ary-tree Easy
75 Tree https://leetcode.com/problems/find-largest-value-in-each-tree-row Medium
76 Tree https://leetcode.com/problems/minimum-absolute-difference-in-bst Easy
77 Tree https://leetcode.com/problems/smallest-subtree-with-all-the-deepest-nodes Medium
78 Tree https://leetcode.com/problems/check-completeness-of-a-binary-tree Medium
79 Tree https://leetcode.com/problems/sum-of-root-to-leaf-binary-numbers Easy
80 Tree https://leetcode.com/problems/construct-binary-tree-from-preorder-and-postorder-traversal
Medium
81 Tree https://leetcode.com/problems/n-ary-tree-level-order-traversal Medium
82 Tree https://leetcode.com/problems/verify-preorder-serialization-of-a-binary-tree Medium
83 Tree https://leetcode.com/problems/leaf-similar-trees Easy
84 Tree https://leetcode.com/problems/sum-of-nodes-with-even-valued-grandparent Medium
85 Tree https://leetcode.com/problems/binary-tree-tilt Easy
86 Tree https://leetcode.com/problems/n-ary-tree-preorder-traversal Easy
87 Tree https://leetcode.com/problems/flip-equivalent-binary-trees Medium
88 Tree https://leetcode.com/problems/balance-a-binary-search-tree Medium
89 Tree https://leetcode.com/problems/minimum-distance-between-bst-nodes Easy
90 Tree https://leetcode.com/problems/n-ary-tree-postorder-traversal Easy
91 Tree https://leetcode.com/problems/all-elements-in-two-binary-search-trees Medium
92 Tree https://leetcode.com/problems/time-needed-to-inform-all-employees Medium
93 Tree https://leetcode.com/problems/most-frequent-subtree-sum Medium
94 Tree https://leetcode.com/problems/construct-string-from-binary-tree Easy
95 Tree https://leetcode.com/problems/maximum-level-sum-of-a-binary-tree Medium
96 Tree https://leetcode.com/problems/delete-leaves-with-a-given-value Medium
97 Tree https://leetcode.com/problems/linked-list-in-binary-tree Medium
98 Tree https://leetcode.com/problems/add-one-row-to-tree Medium
99 Tree https://leetcode.com/problems/univalued-binary-tree Easy
100 Tree https://leetcode.com/problems/maximum-product-of-splitted-binary-tree Medium
101 Tree https://leetcode.com/problems/second-minimum-node-in-a-binary-tree Easy
102 Tree https://leetcode.com/problems/lowest-common-ancestor-of-deepest-leaves Medium
103 Tree https://leetcode.com/problems/number-of-good-leaf-nodes-pairs Medium
104 Tree https://leetcode.com/problems/smallest-string-starting-from-leaf Medium
105 Tree https://leetcode.com/problems/recover-a-tree-from-preorder-traversal Hard
106 Tree https://leetcode.com/problems/longest-zigzag-path-in-a-binary-tree Medium
107 Tree https://leetcode.com/problems/path-in-zigzag-labelled-binary-tree Medium
108 Tree https://leetcode.com/problems/pseudo-palindromic-paths-in-a-binary-tree Medium
109 Tree https://leetcode.com/problems/binary-tree-coloring-game Medium
110 Tree https://leetcode.com/problems/maximum-sum-bst-in-binary-tree Hard
111 Tree https://leetcode.com/problems/minimum-time-to-collect-all-apples-in-a-tree Medium
112 Tree https://leetcode.com/problems/kth-ancestor-of-a-tree-node Hard
113 Tree https://leetcode.com/problems/complete-binary-tree-inserter Medium
114 Tree https://leetcode.com/problems/flip-binary-tree-to-match-preorder-traversal Medium
115 Tree https://leetcode.com/problems/validate-binary-tree-nodes Medium
116 Tree https://leetcode.com/problems/find-a-corresponding-node-of-a-binary-tree-in-a-clone-of-that-tree
Medium
117 Tree https://leetcode.com/problems/even-odd-tree Medium
118 Tree https://leetcode.com/problems/find-elements-in-a-contaminated-binary-tree Medium
119 Tree https://leetcode.com/problems/construct-quad-tree Medium
120 Tree https://leetcode.com/problems/insufficient-nodes-in-root-to-leaf-paths Medium
121 Tree https://leetcode.com/problems/number-of-ways-to-reorder-array-to-get-same-bstHard
122 Tree https://leetcode.com/problems/frog-position-after-t-seconds Hard
123 Tree https://leetcode.com/problems/step-by-step-directions-from-a-binary-tree-node-to-another
Medium
124 Tree https://leetcode.com/problems/number-of-nodes-in-the-sub-tree-with-the-same-label
Medium
125 Tree https://leetcode.com/problems/maximum-binary-tree-ii Medium
126 Tree https://leetcode.com/problems/count-nodes-with-the-highest-score Medium
127 Tree https://leetcode.com/problems/count-subtrees-with-max-distance-between-citiesHard
128 Tree https://leetcode.com/problems/smallest-missing-genetic-value-in-each-subtree Hard
129 Tree https://leetcode.com/problems/count-ways-to-build-rooms-in-an-ant-colony Hard
130 Tree https://leetcode.com/problems/tree-of-coprimes Hard
131 Tree https://leetcode.com/problems/merge-bsts-to-create-single-bst Hard
132 Tree https://leetcode.com/problems/operations-on-tree Medium
133 Tree https://leetcode.com/problems/throne-inheritance Medium
134 Tree https://leetcode.com/problems/logical-or-of-two-binary-grids-represented-as-quad-trees
Medium
135 Tree https://leetcode.com/problems/print-binary-tree Medium
136 Tree https://leetcode.com/problems/number-of-ways-to-reconstruct-a-tree Hard
 Crack The Coding Interview - Dinesh Varyani
https://www.youtube.com/user/hubberspot?sub_confirmation=1

# Topic Question Difficulty

1 Matrix https://leetcode.com/problems/number-of-islands Medium

2 Matrix https://leetcode.com/problems/word-search Medium
3 Matrix https://leetcode.com/problems/rotate-image Medium
4 Matrix https://leetcode.com/problems/maximal-square Medium
5 Matrix https://leetcode.com/problems/minimum-path-sum Medium
6 Matrix https://leetcode.com/problems/search-a-2d-matrix-ii Medium
7 Matrix https://leetcode.com/problems/maximal-rectangle Hard
8 Matrix https://leetcode.com/problems/spiral-matrix Medium
9 Matrix https://leetcode.com/problems/rotting-oranges Medium
10 Matrix https://leetcode.com/problems/set-matrix-zeroes Medium
11 Matrix https://leetcode.com/problems/search-a-2d-matrix Medium
12 Matrix https://leetcode.com/problems/word-search-ii Hard
13 Matrix https://leetcode.com/problems/kth-smallest-element-in-a-sorted-matrix Medium
14 Matrix https://leetcode.com/problems/max-area-of-island Medium
15 Matrix https://leetcode.com/problems/sudoku-solver Hard
16 Matrix https://leetcode.com/problems/surrounded-regions Medium
17 Matrix https://leetcode.com/problems/valid-sudoku Medium
18 Matrix https://leetcode.com/problems/unique-paths-ii Medium
19 Matrix https://leetcode.com/problems/island-perimeter Easy
20 Matrix https://leetcode.com/problems/01-matrix Medium
21 Matrix https://leetcode.com/problems/dungeon-game Hard
22 Matrix https://leetcode.com/problems/game-of-life Medium
23 Matrix https://leetcode.com/problems/flood-fill Easy
24 Matrix https://leetcode.com/problems/pacific-atlantic-water-flow Medium
25 Matrix https://leetcode.com/problems/count-square-submatrices-with-all-ones Medium
26 Matrix https://leetcode.com/problems/unique-paths-iii Hard
27 Matrix https://leetcode.com/problems/trapping-rain-water-ii Hard
28 Matrix https://leetcode.com/problems/spiral-matrix-ii Medium
29 Matrix https://leetcode.com/problems/range-sum-query-2d-immutable Medium
30 Matrix https://leetcode.com/problems/cherry-pickup Hard
31 Matrix https://leetcode.com/problems/shortest-bridge Medium
32 Matrix https://leetcode.com/problems/making-a-large-island Hard
33 Matrix https://leetcode.com/problems/shortest-path-in-binary-matrix Medium
34 Matrix https://leetcode.com/problems/minimum-falling-path-sum Medium
35 Matrix https://leetcode.com/problems/diagonal-traverse Medium
36 Matrix https://leetcode.com/problems/path-with-minimum-effort Medium
37 Matrix https://leetcode.com/problems/flipping-an-image Easy
38 Matrix https://leetcode.com/problems/max-sum-of-rectangle-no-larger-than-k Hard
39 Matrix https://leetcode.com/problems/count-negative-numbers-in-a-sorted-matrix Easy
40 Matrix https://leetcode.com/problems/reshape-the-matrix Easy
41 Matrix https://leetcode.com/problems/toeplitz-matrix Easy
42 Matrix https://leetcode.com/problems/shortest-path-in-a-grid-with-obstacles-eliminationHard
43 Matrix https://leetcode.com/problems/swim-in-rising-water Hard
44 Matrix https://leetcode.com/problems/path-with-maximum-gold Medium
45 Matrix https://leetcode.com/problems/max-increase-to-keep-city-skyline Medium
46 Matrix https://leetcode.com/problems/matrix-block-sum Medium
47 Matrix https://leetcode.com/problems/number-of-submatrices-that-sum-to-target Hard
48 Matrix https://leetcode.com/problems/sort-the-matrix-diagonally Medium
49 Matrix https://leetcode.com/problems/number-of-closed-islands Medium
50 Matrix https://leetcode.com/problems/the-k-weakest-rows-in-a-matrix Easy
51 Matrix https://leetcode.com/problems/count-submatrices-with-all-ones Medium
52 Matrix https://leetcode.com/problems/as-far-from-land-as-possible Medium
53 Matrix https://leetcode.com/problems/sliding-puzzle Hard
54 Matrix https://leetcode.com/problems/battleships-in-a-board Medium
55 Matrix https://leetcode.com/problems/minesweeper Medium
56 Matrix https://leetcode.com/problems/cherry-pickup-ii Hard
57 Matrix https://leetcode.com/problems/richest-customer-wealth Easy
58 Matrix https://leetcode.com/problems/transpose-matrix Easy
59 Matrix https://leetcode.com/problems/score-after-flipping-matrix Medium
60 Matrix https://leetcode.com/problems/minimum-cost-to-make-at-least-one-valid-path-in-a-grid
Hard
61 Matrix https://leetcode.com/problems/number-of-enclaves Medium
 62 Matrix https://leetcode.com/problems/cut-off-trees-for-golf-event Hard
63 Matrix https://leetcode.com/problems/matrix-diagonal-sum Easy
64 Matrix https://leetcode.com/problems/count-servers-that-communicate Medium
65 Matrix https://leetcode.com/problems/lucky-numbers-in-a-matrix Easy
66 Matrix https://leetcode.com/problems/find-valid-matrix-given-row-and-column-sums Medium
67 Matrix https://leetcode.com/problems/find-the-kth-smallest-sum-of-a-matrix-with-sorted-rows
Hard
68 Matrix https://leetcode.com/problems/bricks-falling-when-hit Hard
69 Matrix https://leetcode.com/problems/maximum-side-length-of-a-square-with-sum-less-than-or-equal-to-threshold
Medium
70 Matrix https://leetcode.com/problems/find-winner-on-a-tic-tac-toe-game Easy
71 Matrix https://leetcode.com/problems/where-will-the-ball-fall Medium
72 Matrix https://leetcode.com/problems/minimum-falling-path-sum-ii Hard
73 Matrix https://leetcode.com/problems/queens-that-can-attack-the-king Medium
74 Matrix https://leetcode.com/problems/count-sub-islands Medium
75 Matrix https://leetcode.com/problems/minimum-moves-to-move-a-box-to-their-target-location
Hard
76 Matrix https://leetcode.com/problems/largest-submatrix-with-rearrangements Medium
77 Matrix https://leetcode.com/problems/minimize-malware-spread Hard
78 Matrix https://leetcode.com/problems/rank-transform-of-a-matrix Hard
79 Matrix https://leetcode.com/problems/maximum-students-taking-exam Hard
80 Matrix https://leetcode.com/problems/check-if-there-is-a-valid-path-in-a-grid Medium
81 Matrix https://leetcode.com/problems/detect-cycles-in-2d-grid Medium
82 Matrix https://leetcode.com/problems/find-a-peak-element-ii Medium
83 Matrix https://leetcode.com/problems/flip-columns-for-maximum-number-of-equal-rowsMedium
84 Matrix https://leetcode.com/problems/maximum-non-negative-product-in-a-matrix Medium
85 Matrix https://leetcode.com/problems/minimum-number-of-flips-to-convert-binary-matrix-to-zero-matrix
Hard
86 Matrix https://leetcode.com/problems/rotating-the-box Medium
87 Matrix https://leetcode.com/problems/largest-1-bordered-square Medium
88 Matrix https://leetcode.com/problems/spiral-matrix-iii Medium
89 Matrix https://leetcode.com/problems/matrix-cells-in-distance-order Easy
90 Matrix https://leetcode.com/problems/map-of-highest-peak Medium
91 Matrix https://leetcode.com/problems/shift-2d-grid Easy
92 Matrix https://leetcode.com/problems/construct-quad-tree Medium
93 Matrix https://leetcode.com/problems/snakes-and-ladders Medium
94 Matrix https://leetcode.com/problems/available-captures-for-rook Easy
95 Matrix https://leetcode.com/problems/determine-whether-matrix-can-be-obtained-by-rotation
Easy
96 Matrix https://leetcode.com/problems/number-of-ways-of-cutting-a-pizza Hard
97 Matrix https://leetcode.com/problems/surface-area-of-3d-shapes Easy
98 Matrix https://leetcode.com/problems/minimize-malware-spread-ii Hard
99 Matrix https://leetcode.com/problems/special-positions-in-a-binary-matrix Easy
100 Matrix https://leetcode.com/problems/minimize-the-difference-between-target-and-chosen-elements
Medium
101 Matrix https://leetcode.com/problems/minimum-swaps-to-arrange-a-binary-grid Medium
102 Matrix https://leetcode.com/problems/last-day-where-you-can-still-cross Hard
103 Matrix https://leetcode.com/problems/projection-area-of-3d-shapes Easy
104 Matrix https://leetcode.com/problems/grid-game Medium
105 Matrix https://leetcode.com/problems/image-smoother Easy
106 Matrix https://leetcode.com/problems/coloring-a-border Medium
107 Matrix https://leetcode.com/problems/minimum-number-of-days-to-disconnect-island Hard
108 Matrix https://leetcode.com/problems/subrectangle-queries Medium
109 Matrix https://leetcode.com/problems/nearest-exit-from-entrance-in-maze Medium
110 Matrix https://leetcode.com/problems/reconstruct-a-2-row-binary-matrix Medium
111 Matrix https://leetcode.com/problems/minimum-cost-to-connect-two-groups-of-points Hard
112 Matrix https://leetcode.com/problems/number-of-paths-with-max-score Hard
113 Matrix https://leetcode.com/problems/strange-printer-ii Hard
114 Matrix https://leetcode.com/problems/transform-to-chessboard Hard
115 Matrix https://leetcode.com/problems/find-kth-largest-xor-coordinate-value Medium
116 Matrix https://leetcode.com/problems/find-all-groups-of-farmland Medium
117 Matrix https://leetcode.com/problems/minimum-operations-to-make-a-uni-value-grid Medium
118 Matrix https://leetcode.com/problems/maximum-matrix-sum Medium
119 Matrix https://leetcode.com/problems/magic-squares-in-grid Medium
120 Matrix https://leetcode.com/problems/contain-virus Hard
121 Matrix https://leetcode.com/problems/minimum-cost-homecoming-of-a-robot-in-a-grid Medium
122 Matrix https://leetcode.com/problems/minimum-moves-to-reach-target-with-rotations Hard
123 Matrix https://leetcode.com/problems/largest-magic-square Medium
124 Matrix https://leetcode.com/problems/convert-1d-array-into-2d-array Easy
125 Matrix https://leetcode.com/problems/cyclically-rotating-a-grid Medium
126 Matrix https://leetcode.com/problems/count-fertile-pyramids-in-a-land Hard
127 Matrix https://leetcode.com/problems/get-biggest-three-rhombus-sums-in-a-grid Medium
128 Matrix https://leetcode.com/problems/check-if-word-can-be-placed-in-crossword Medium
129 Matrix https://leetcode.com/problems/check-if-move-is-legal Medium
130 Matrix https://leetcode.com/problems/image-overlap Medium
 Crack The Coding Interview - Dinesh Varyani
https://www.youtube.com/user/hubberspot?sub_confirmation=1

# Topic Question Difficulty

1 Two Pointers https://leetcode.com/problems/trapping-rain-water Hard

2 Two Pointers https://leetcode.com/problems/3sum Medium
3 Two Pointers https://leetcode.com/problems/container-with-most-water Medium
4 Two Pointers https://leetcode.com/problems/find-the-duplicate-number Medium
5 Two Pointers https://leetcode.com/problems/next-permutation Medium
6 Two Pointers https://leetcode.com/problems/sort-colors Medium
7 Two Pointers https://leetcode.com/problems/remove-nth-node-from-end-of-list Medium
8 Two Pointers https://leetcode.com/problems/move-zeroes Easy
9 Two Pointers https://leetcode.com/problems/intersection-of-two-linked-lists Easy
10 Two Pointers https://leetcode.com/problems/palindrome-linked-list Easy
11 Two Pointers https://leetcode.com/problems/rotate-array Medium
12 Two Pointers https://leetcode.com/problems/linked-list-cycle Easy
13 Two Pointers https://leetcode.com/problems/partition-labels Medium
14 Two Pointers https://leetcode.com/problems/find-median-from-data-stream Hard
15 Two Pointers https://leetcode.com/problems/linked-list-cycle-ii Medium
16 Two Pointers https://leetcode.com/problems/sort-list Medium
17 Two Pointers https://leetcode.com/problems/remove-duplicates-from-sorted-array Easy
18 Two Pointers https://leetcode.com/problems/4sum Medium
19 Two Pointers https://leetcode.com/problems/reorder-list Medium
20 Two Pointers https://leetcode.com/problems/3sum-closest Medium
21 Two Pointers https://leetcode.com/problems/shortest-unsorted-continuous-subarray Medium
22 Two Pointers https://leetcode.com/problems/happy-number Easy
23 Two Pointers https://leetcode.com/problems/middle-of-the-linked-list Easy
24 Two Pointers https://leetcode.com/problems/two-sum-ii-input-array-is-sorted Easy
25 Two Pointers https://leetcode.com/problems/squares-of-a-sorted-array Easy
26 Two Pointers https://leetcode.com/problems/remove-duplicates-from-sorted-list-ii Medium
27 Two Pointers https://leetcode.com/problems/permutation-in-string Medium
28 Two Pointers https://leetcode.com/problems/valid-palindrome-ii Easy
29 Two Pointers https://leetcode.com/problems/interval-list-intersections Medium
30 Two Pointers https://leetcode.com/problems/rotate-list Medium
31 Two Pointers https://leetcode.com/problems/intersection-of-two-arrays-ii Easy
32 Two Pointers https://leetcode.com/problems/find-k-closest-elements Medium
33 Two Pointers https://leetcode.com/problems/reverse-string Easy
34 Two Pointers https://leetcode.com/problems/is-subsequence Easy
35 Two Pointers https://leetcode.com/problems/backspace-string-compare Easy
36 Two Pointers https://leetcode.com/problems/implement-strstr Easy
37 Two Pointers https://leetcode.com/problems/two-sum-iv-input-is-a-bst Easy
38 Two Pointers https://leetcode.com/problems/partition-list Medium
39 Two Pointers https://leetcode.com/problems/remove-element Easy
40 Two Pointers https://leetcode.com/problems/longest-string-chain Medium
41 Two Pointers https://leetcode.com/problems/valid-palindrome Easy
42 Two Pointers https://leetcode.com/problems/merge-sorted-array Easy
43 Two Pointers https://leetcode.com/problems/reverse-words-in-a-string Medium
44 Two Pointers https://leetcode.com/problems/remove-duplicates-from-sorted-array-ii Medium
45 Two Pointers https://leetcode.com/problems/count-binary-substrings Easy
46 Two Pointers https://leetcode.com/problems/sort-array-by-parity Easy
47 Two Pointers https://leetcode.com/problems/intersection-of-two-arrays Easy
48 Two Pointers https://leetcode.com/problems/valid-triangle-number Medium
49 Two Pointers https://leetcode.com/problems/reverse-words-in-a-string-iii Easy
50 Two Pointers https://leetcode.com/problems/shortest-distance-to-a-character Easy
51 Two Pointers https://leetcode.com/problems/next-greater-element-iii Medium
52 Two Pointers https://leetcode.com/problems/flipping-an-image Easy
53 Two Pointers https://leetcode.com/problems/string-compression Medium
54 Two Pointers https://leetcode.com/problems/find-k-th-smallest-pair-distance Hard
55 Two Pointers https://leetcode.com/problems/boats-to-save-people Medium
56 Two Pointers https://leetcode.com/problems/longest-mountain-in-array Medium
57 Two Pointers https://leetcode.com/problems/sort-array-by-parity-ii Easy
58 Two Pointers https://leetcode.com/problems/k-diff-pairs-in-an-array Medium
59 Two Pointers https://leetcode.com/problems/di-string-match Easy
60 Two Pointers https://leetcode.com/problems/push-dominoes Medium
61 Two Pointers https://leetcode.com/problems/number-of-subarrays-with-bounded-maximum Medium
 62 Two Pointers https://leetcode.com/problems/long-pressed-name Easy
63 Two Pointers https://leetcode.com/problems/duplicate-zeros Easy
64 Two Pointers https://leetcode.com/problems/reverse-vowels-of-a-string Easy
65 Two Pointers https://leetcode.com/problems/reverse-only-letters Easy
66 Two Pointers https://leetcode.com/problems/swapping-nodes-in-a-linked-list Medium
67 Two Pointers https://leetcode.com/problems/longest-word-in-dictionary-through-deleting Medium
68 Two Pointers https://leetcode.com/problems/heaters Medium
69 Two Pointers https://leetcode.com/problems/sum-of-square-numbers Medium
70 Two Pointers https://leetcode.com/problems/compare-version-numbers Medium
71 Two Pointers https://leetcode.com/problems/pancake-sorting Medium
72 Two Pointers https://leetcode.com/problems/number-of-subsequences-that-satisfy-the-given-sum-condition
Medium
73 Two Pointers https://leetcode.com/problems/3sum-with-multiplicity Medium
74 Two Pointers https://leetcode.com/problems/shortest-subarray-to-be-removed-to-make-array-sorted
Medium
75 Two Pointers https://leetcode.com/problems/reverse-string-ii Easy
76 Two Pointers https://leetcode.com/problems/most-profit-assigning-work Medium
77 Two Pointers https://leetcode.com/problems/swap-adjacent-in-lr-string Medium
78 Two Pointers https://leetcode.com/problems/jump-game-vii Medium
79 Two Pointers https://leetcode.com/problems/check-if-n-and-its-double-exist Easy
80 Two Pointers https://leetcode.com/problems/ways-to-split-array-into-three-subarrays Medium
81 Two Pointers https://leetcode.com/problems/expressive-words Medium
82 Two Pointers https://leetcode.com/problems/bag-of-tokens Medium
83 Two Pointers https://leetcode.com/problems/max-number-of-k-sum-pairs Medium
84 Two Pointers https://leetcode.com/problems/get-the-maximum-score Hard
85 Two Pointers https://leetcode.com/problems/camelcase-matching Medium
86 Two Pointers https://leetcode.com/problems/friends-of-appropriate-ages Medium
87 Two Pointers https://leetcode.com/problems/minimum-number-of-swaps-to-make-the-string-balancedMedium
88 Two Pointers https://leetcode.com/problems/range-sum-of-sorted-subarray-sums Medium
89 Two Pointers https://leetcode.com/problems/maximum-score-of-a-good-subarray Hard
90 Two Pointers https://leetcode.com/problems/minimize-maximum-pair-sum-in-array Medium
91 Two Pointers https://leetcode.com/problems/rotating-the-box Medium
92 Two Pointers https://leetcode.com/problems/split-two-strings-to-make-palindrome Medium
93 Two Pointers https://leetcode.com/problems/last-substring-in-lexicographical-order Hard
94 Two Pointers https://leetcode.com/problems/maximum-distance-between-a-pair-of-values Medium
95 Two Pointers https://leetcode.com/problems/longest-chunked-palindrome-decomposition Hard
96 Two Pointers https://leetcode.com/problems/merge-strings-alternately Easy
97 Two Pointers https://leetcode.com/problems/closest-subsequence-sum Hard
98 Two Pointers https://leetcode.com/problems/the-k-strongest-values-in-an-array Medium
99 Two Pointers https://leetcode.com/problems/longest-uncommon-subsequence-ii Medium
100 Two Pointers https://leetcode.com/problems/minimum-adjacent-swaps-to-reach-the-kth-smallest-number
Medium
101 Two Pointers https://leetcode.com/problems/delete-the-middle-node-of-a-linked-list Medium
102 Two Pointers https://leetcode.com/problems/find-positive-integer-solution-for-a-given-equationMedium
103 Two Pointers https://leetcode.com/problems/largest-merge-of-two-strings Medium
104 Two Pointers https://leetcode.com/problems/partition-array-into-two-arrays-to-minimize-sum-difference
Hard
105 Two Pointers https://leetcode.com/problems/circular-array-loop Medium
106 Two Pointers https://leetcode.com/problems/moving-stones-until-consecutive-ii Medium
107 Two Pointers https://leetcode.com/problems/find-the-distance-value-between-two-arrays Easy
108 Two Pointers https://leetcode.com/problems/minimum-length-of-string-after-deleting-similar-ends
Medium
109 Two Pointers https://leetcode.com/problems/number-of-ways-where-square-of-number-is-equal-to-product-of-two-numbers
Medium
110 Two Pointers https://leetcode.com/problems/reverse-prefix-of-word Easy
111 Two Pointers https://leetcode.com/problems/sentence-similarity-iii Medium
112 Two Pointers https://leetcode.com/problems/count-pairs-of-nodes Hard
113 Two Pointers https://leetcode.com/problems/magical-string Medium
114 Two Pointers https://leetcode.com/problems/remove-palindromic-subsequences Easy
115 Two Pointers https://leetcode.com/problems/find-first-palindromic-string-in-the-array Easy
116 Two Pointers https://leetcode.com/problems/watering-plants-ii Medium
117 Two Pointers https://leetcode.com/problems/statistics-from-a-large-sample Medium
 Crack The Coding Interview - Dinesh Varyani
https://www.youtube.com/user/hubberspot?sub_confirmation=1

# Topic Question Difficulty

1 Binary Tree https://leetcode.com/problems/validate-binary-search-tree Medium

2 Binary Tree https://leetcode.com/problems/lowest-common-ancestor-of-a-binary-tree Medium
3 Binary Tree https://leetcode.com/problems/symmetric-tree Easy
4 Binary Tree https://leetcode.com/problems/binary-tree-maximum-path-sum Hard
5 Binary Tree https://leetcode.com/problems/construct-binary-tree-from-preorder-and-inorder-traversal
Medium
6 Binary Tree https://leetcode.com/problems/invert-binary-tree Easy
7 Binary Tree https://leetcode.com/problems/path-sum-iii Medium
8 Binary Tree https://leetcode.com/problems/binary-tree-level-order-traversal Medium
9 Binary Tree https://leetcode.com/problems/diameter-of-binary-tree Easy
10 Binary Tree https://leetcode.com/problems/binary-tree-inorder-traversal Easy
11 Binary Tree https://leetcode.com/problems/unique-binary-search-trees Medium
12 Binary Tree https://leetcode.com/problems/flatten-binary-tree-to-linked-list Medium
13 Binary Tree https://leetcode.com/problems/merge-two-binary-trees Easy
14 Binary Tree https://leetcode.com/problems/serialize-and-deserialize-binary-tree Hard
15 Binary Tree https://leetcode.com/problems/house-robber-iii Medium
16 Binary Tree https://leetcode.com/problems/binary-tree-right-side-view Medium
17 Binary Tree https://leetcode.com/problems/maximum-depth-of-binary-tree Easy
18 Binary Tree https://leetcode.com/problems/convert-sorted-array-to-binary-search-tree Easy
19 Binary Tree https://leetcode.com/problems/populating-next-right-pointers-in-each-node Medium
20 Binary Tree https://leetcode.com/problems/kth-smallest-element-in-a-bst Medium
21 Binary Tree https://leetcode.com/problems/all-nodes-distance-k-in-binary-tree Medium
22 Binary Tree https://leetcode.com/problems/binary-tree-zigzag-level-order-traversal Medium
23 Binary Tree https://leetcode.com/problems/balanced-binary-tree Easy
24 Binary Tree https://leetcode.com/problems/same-tree Easy
25 Binary Tree https://leetcode.com/problems/lowest-common-ancestor-of-a-binary-search-tree Easy
26 Binary Tree https://leetcode.com/problems/binary-search-tree-iterator Medium
27 Binary Tree https://leetcode.com/problems/path-sum Easy
28 Binary Tree https://leetcode.com/problems/delete-node-in-a-bst Medium
29 Binary Tree https://leetcode.com/problems/subtree-of-another-tree Easy
30 Binary Tree https://leetcode.com/problems/unique-binary-search-trees-ii Medium
31 Binary Tree https://leetcode.com/problems/count-complete-tree-nodes Medium
32 Binary Tree https://leetcode.com/problems/path-sum-ii Medium
33 Binary Tree https://leetcode.com/problems/convert-sorted-list-to-binary-search-tree Medium
34 Binary Tree https://leetcode.com/problems/construct-binary-tree-from-inorder-and-postorder-traversal
Medium
35 Binary Tree https://leetcode.com/problems/sum-root-to-leaf-numbers Medium
36 Binary Tree https://leetcode.com/problems/recover-binary-search-tree Medium
37 Binary Tree https://leetcode.com/problems/range-sum-of-bst Easy
38 Binary Tree https://leetcode.com/problems/binary-tree-postorder-traversal Easy
39 Binary Tree https://leetcode.com/problems/binary-tree-paths Easy
40 Binary Tree https://leetcode.com/problems/minimum-depth-of-binary-tree Easy
41 Binary Tree https://leetcode.com/problems/binary-tree-preorder-traversal Easy
42 Binary Tree https://leetcode.com/problems/trim-a-binary-search-tree Medium
43 Binary Tree https://leetcode.com/problems/populating-next-right-pointers-in-each-node-ii Medium
44 Binary Tree https://leetcode.com/problems/maximum-binary-tree Medium
45 Binary Tree https://leetcode.com/problems/distribute-coins-in-binary-tree Medium
46 Binary Tree https://leetcode.com/problems/maximum-width-of-binary-tree Medium
47 Binary Tree https://leetcode.com/problems/construct-binary-search-tree-from-preorder-traversal
Medium
48 Binary Tree https://leetcode.com/problems/two-sum-iv-input-is-a-bst Easy
49 Binary Tree https://leetcode.com/problems/convert-bst-to-greater-tree Medium
50 Binary Tree https://leetcode.com/problems/sum-of-left-leaves Easy
51 Binary Tree https://leetcode.com/problems/longest-univalue-path Medium
52 Binary Tree https://leetcode.com/problems/binary-tree-level-order-traversal-ii Medium
53 Binary Tree https://leetcode.com/problems/find-duplicate-subtrees Medium
54 Binary Tree https://leetcode.com/problems/average-of-levels-in-binary-tree Easy
55 Binary Tree https://leetcode.com/problems/delete-nodes-and-return-forest Medium
56 Binary Tree https://leetcode.com/problems/vertical-order-traversal-of-a-binary-tree Hard
57 Binary Tree https://leetcode.com/problems/serialize-and-deserialize-bst Medium
58 Binary Tree https://leetcode.com/problems/cousins-in-binary-tree Easy
59 Binary Tree https://leetcode.com/problems/binary-tree-cameras Hard
60 Binary Tree https://leetcode.com/problems/insert-into-a-binary-search-tree Medium
61 Binary Tree https://leetcode.com/problems/search-in-a-binary-search-tree Easy
 62 Binary Tree https://leetcode.com/problems/all-possible-full-binary-trees Medium
63 Binary Tree https://leetcode.com/problems/binary-tree-pruning Medium
64 Binary Tree https://leetcode.com/problems/binary-search-tree-to-greater-sum-tree Medium
65 Binary Tree https://leetcode.com/problems/maximum-difference-between-node-and-ancestorMedium
66 Binary Tree https://leetcode.com/problems/deepest-leaves-sum Medium
67 Binary Tree https://leetcode.com/problems/increasing-order-search-tree Easy
68 Binary Tree https://leetcode.com/problems/count-good-nodes-in-binary-tree Medium
69 Binary Tree https://leetcode.com/problems/find-mode-in-binary-search-tree Easy
70 Binary Tree https://leetcode.com/problems/find-bottom-left-tree-value Medium
71 Binary Tree https://leetcode.com/problems/kth-largest-element-in-a-stream Easy
72 Binary Tree https://leetcode.com/problems/find-largest-value-in-each-tree-row Medium
73 Binary Tree https://leetcode.com/problems/minimum-absolute-difference-in-bst Easy
74 Binary Tree https://leetcode.com/problems/smallest-subtree-with-all-the-deepest-nodes Medium
75 Binary Tree https://leetcode.com/problems/check-completeness-of-a-binary-tree Medium
76 Binary Tree https://leetcode.com/problems/sum-of-root-to-leaf-binary-numbers Easy
77 Binary Tree https://leetcode.com/problems/construct-binary-tree-from-preorder-and-postorder-traversal
Medium
78 Binary Tree https://leetcode.com/problems/verify-preorder-serialization-of-a-binary-tree Medium
79 Binary Tree https://leetcode.com/problems/leaf-similar-trees Easy
80 Binary Tree https://leetcode.com/problems/sum-of-nodes-with-even-valued-grandparent Medium
81 Binary Tree https://leetcode.com/problems/binary-tree-tilt Easy
82 Binary Tree https://leetcode.com/problems/flip-equivalent-binary-trees Medium
83 Binary Tree https://leetcode.com/problems/balance-a-binary-search-tree Medium
84 Binary Tree https://leetcode.com/problems/minimum-distance-between-bst-nodes Easy
85 Binary Tree https://leetcode.com/problems/all-elements-in-two-binary-search-trees Medium
86 Binary Tree https://leetcode.com/problems/most-frequent-subtree-sum Medium
87 Binary Tree https://leetcode.com/problems/construct-string-from-binary-tree Easy
88 Binary Tree https://leetcode.com/problems/maximum-level-sum-of-a-binary-tree Medium
89 Binary Tree https://leetcode.com/problems/delete-leaves-with-a-given-value Medium
90 Binary Tree https://leetcode.com/problems/linked-list-in-binary-tree Medium
91 Binary Tree https://leetcode.com/problems/add-one-row-to-tree Medium
92 Binary Tree https://leetcode.com/problems/univalued-binary-tree Easy
93 Binary Tree https://leetcode.com/problems/maximum-product-of-splitted-binary-tree Medium
94 Binary Tree https://leetcode.com/problems/second-minimum-node-in-a-binary-tree Easy
95 Binary Tree https://leetcode.com/problems/lowest-common-ancestor-of-deepest-leaves Medium
96 Binary Tree https://leetcode.com/problems/number-of-good-leaf-nodes-pairs Medium
97 Binary Tree https://leetcode.com/problems/smallest-string-starting-from-leaf Medium
98 Binary Tree https://leetcode.com/problems/recover-a-tree-from-preorder-traversal Hard
99 Binary Tree https://leetcode.com/problems/longest-zigzag-path-in-a-binary-tree Medium
100 Binary Tree https://leetcode.com/problems/path-in-zigzag-labelled-binary-tree Medium
101 Binary Tree https://leetcode.com/problems/pseudo-palindromic-paths-in-a-binary-tree Medium
102 Binary Tree https://leetcode.com/problems/binary-tree-coloring-game Medium
103 Binary Tree https://leetcode.com/problems/maximum-sum-bst-in-binary-tree Hard
104 Binary Tree https://leetcode.com/problems/complete-binary-tree-inserter Medium
105 Binary Tree https://leetcode.com/problems/flip-binary-tree-to-match-preorder-traversal Medium
106 Binary Tree https://leetcode.com/problems/validate-binary-tree-nodes Medium
107 Binary Tree https://leetcode.com/problems/find-a-corresponding-node-of-a-binary-tree-in-a-clone-of-that-tree
Medium
108 Binary Tree https://leetcode.com/problems/even-odd-tree Medium
109 Binary Tree https://leetcode.com/problems/find-elements-in-a-contaminated-binary-tree Medium
110 Binary Tree https://leetcode.com/problems/insufficient-nodes-in-root-to-leaf-paths Medium
111 Binary Tree https://leetcode.com/problems/number-of-ways-to-reorder-array-to-get-same-bstHard
112 Binary Tree https://leetcode.com/problems/step-by-step-directions-from-a-binary-tree-node-to-another
Medium
113 Binary Tree https://leetcode.com/problems/maximum-binary-tree-ii Medium
114 Binary Tree https://leetcode.com/problems/count-nodes-with-the-highest-score Medium
115 Binary Tree https://leetcode.com/problems/merge-bsts-to-create-single-bst Hard
116 Binary Tree https://leetcode.com/problems/print-binary-tree Medium
 Crack The Coding Interview - Dinesh Varyani
https://www.youtube.com/user/hubberspot?sub_confirmation=1

# Topic Question Difficulty

1 Bit Manipulation https://leetcode.com/problems/find-the-duplicate-number Medium

2 Bit Manipulation https://leetcode.com/problems/single-number Easy
3 Bit Manipulation https://leetcode.com/problems/subsets Medium
4 Bit Manipulation https://leetcode.com/problems/counting-bits Easy
5 Bit Manipulation https://leetcode.com/problems/missing-number Easy
6 Bit Manipulation https://leetcode.com/problems/partition-to-k-equal-sum-subsets Medium
7 Bit Manipulation https://leetcode.com/problems/subsets-ii Medium
8 Bit Manipulation https://leetcode.com/problems/add-binary Easy
9 Bit Manipulation https://leetcode.com/problems/single-number-ii Medium
10 Bit Manipulation https://leetcode.com/problems/single-number-iii Medium
11 Bit Manipulation https://leetcode.com/problems/hamming-distance Easy
12 Bit Manipulation https://leetcode.com/problems/letter-case-permutation Medium
13 Bit Manipulation https://leetcode.com/problems/maximum-xor-of-two-numbers-in-an-array Medium
14 Bit Manipulation https://leetcode.com/problems/power-of-two Easy
15 Bit Manipulation https://leetcode.com/problems/reverse-bits Easy
16 Bit Manipulation https://leetcode.com/problems/unique-paths-iii Hard
17 Bit Manipulation https://leetcode.com/problems/divide-two-integers Medium
18 Bit Manipulation https://leetcode.com/problems/number-of-1-bits Easy
19 Bit Manipulation https://leetcode.com/problems/sum-of-two-integers Medium
20 Bit Manipulation https://leetcode.com/problems/bitwise-and-of-numbers-range Medium
21 Bit Manipulation https://leetcode.com/problems/beautiful-arrangement Medium
22 Bit Manipulation https://leetcode.com/problems/number-complement Easy
23 Bit Manipulation https://leetcode.com/problems/find-the-difference Easy
24 Bit Manipulation https://leetcode.com/problems/can-i-win Medium
25 Bit Manipulation https://leetcode.com/problems/repeated-dna-sequences Medium
26 Bit Manipulation https://leetcode.com/problems/set-mismatch Easy
27 Bit Manipulation https://leetcode.com/problems/maximum-product-of-word-lengths Medium
28 Bit Manipulation https://leetcode.com/problems/maximum-length-of-a-concatenated-string-with-unique-characters
Medium
29 Bit Manipulation https://leetcode.com/problems/total-hamming-distance Medium
30 Bit Manipulation https://leetcode.com/problems/matchsticks-to-square Medium
31 Bit Manipulation https://leetcode.com/problems/k-th-symbol-in-grammar Medium
32 Bit Manipulation https://leetcode.com/problems/number-of-steps-to-reduce-a-number-to-zero Easy
33 Bit Manipulation https://leetcode.com/problems/increasing-subsequences Medium
34 Bit Manipulation https://leetcode.com/problems/gray-code Medium
35 Bit Manipulation https://leetcode.com/problems/shortest-path-visiting-all-nodes Hard
36 Bit Manipulation https://leetcode.com/problems/power-of-four Easy
37 Bit Manipulation https://leetcode.com/problems/prison-cells-after-n-days Medium
38 Bit Manipulation https://leetcode.com/problems/number-of-good-ways-to-split-a-string Medium
39 Bit Manipulation https://leetcode.com/problems/number-of-valid-words-for-each-puzzle Hard
40 Bit Manipulation https://leetcode.com/problems/find-the-longest-substring-containing-vowels-in-even-counts
Medium
41 Bit Manipulation https://leetcode.com/problems/find-the-shortest-superstring Hard
42 Bit Manipulation https://leetcode.com/problems/score-after-flipping-matrix Medium
43 Bit Manipulation https://leetcode.com/problems/shopping-offers Medium
44 Bit Manipulation https://leetcode.com/problems/bitwise-ors-of-subarrays Medium
45 Bit Manipulation https://leetcode.com/problems/binary-watch Easy
46 Bit Manipulation https://leetcode.com/problems/pseudo-palindromic-paths-in-a-binary-tree Medium
47 Bit Manipulation https://leetcode.com/problems/binary-number-with-alternating-bits Easy
48 Bit Manipulation https://leetcode.com/problems/convert-a-number-to-hexadecimal Easy
49 Bit Manipulation https://leetcode.com/problems/count-triplets-that-can-form-two-arrays-of-equal-xor
Medium
50 Bit Manipulation https://leetcode.com/problems/sort-integers-by-the-number-of-1-bits Easy
51 Bit Manipulation https://leetcode.com/problems/xor-queries-of-a-subarray Medium
52 Bit Manipulation https://leetcode.com/problems/split-array-with-same-average Hard
53 Bit Manipulation https://leetcode.com/problems/integer-replacement Medium
54 Bit Manipulation https://leetcode.com/problems/shortest-path-to-get-all-keys Hard
55 Bit Manipulation https://leetcode.com/problems/minimum-number-of-k-consecutive-bit-flips Hard
56 Bit Manipulation https://leetcode.com/problems/xor-operation-in-an-array Easy
57 Bit Manipulation https://leetcode.com/problems/complement-of-base-10-integer Easy
58 Bit Manipulation https://leetcode.com/problems/stickers-to-spell-word Hard
59 Bit Manipulation https://leetcode.com/problems/count-the-number-of-consistent-strings Easy
60 Bit Manipulation https://leetcode.com/problems/check-if-a-string-contains-all-binary-codes-of-size-k
Medium
61 Bit Manipulation https://leetcode.com/problems/smallest-sufficient-team Hard
 62 Bit Manipulation https://leetcode.com/problems/number-of-squareful-arrays Hard
63 Bit Manipulation https://leetcode.com/problems/sum-of-all-subset-xor-totals Easy
64 Bit Manipulation https://leetcode.com/problems/decode-xored-array Easy
65 Bit Manipulation https://leetcode.com/problems/number-of-wonderful-substrings Medium
66 Bit Manipulation https://leetcode.com/problems/maximum-score-words-formed-by-letters Hard
67 Bit Manipulation https://leetcode.com/problems/number-of-ways-to-wear-different-hats-to-each-other
Hard
68 Bit Manipulation https://leetcode.com/problems/parallel-courses-ii Hard
69 Bit Manipulation https://leetcode.com/problems/maximum-students-taking-exam Hard
70 Bit Manipulation https://leetcode.com/problems/can-make-palindrome-from-substring Medium
71 Bit Manipulation https://leetcode.com/problems/find-longest-awesome-substring Hard
72 Bit Manipulation https://leetcode.com/problems/minimum-number-of-flips-to-convert-binary-matrix-to-zero-matrix
Hard
73 Bit Manipulation https://leetcode.com/problems/pyramid-transition-matrix Medium
74 Bit Manipulation https://leetcode.com/problems/find-minimum-time-to-finish-all-jobs Hard
75 Bit Manipulation https://leetcode.com/problems/decode-xored-permutation Medium
76 Bit Manipulation https://leetcode.com/problems/number-of-steps-to-reduce-a-number-in-binary-representation-to-one
Medium
77 Bit Manipulation https://leetcode.com/problems/prime-number-of-set-bits-in-binary-representationEasy
78 Bit Manipulation https://leetcode.com/problems/longest-nice-substring Easy
79 Bit Manipulation https://leetcode.com/problems/minimum-number-of-work-sessions-to-finish-the-tasks
Medium
80 Bit Manipulation https://leetcode.com/problems/binary-gap Easy
81 Bit Manipulation https://leetcode.com/problems/cinema-seat-allocation Medium
82 Bit Manipulation https://leetcode.com/problems/minimum-flips-to-make-a-or-b-equal-to-c Medium
83 Bit Manipulation https://leetcode.com/problems/closest-subsequence-sum Hard
84 Bit Manipulation https://leetcode.com/problems/maximum-compatibility-score-sum Medium
85 Bit Manipulation https://leetcode.com/problems/maximum-xor-with-an-element-from-array Hard
86 Bit Manipulation https://leetcode.com/problems/utf-8-validation Medium
87 Bit Manipulation https://leetcode.com/problems/minimum-xor-sum-of-two-arrays Hard
88 Bit Manipulation https://leetcode.com/problems/maximum-product-of-the-length-of-two-palindromic-subsequences
Medium
89 Bit Manipulation https://leetcode.com/problems/maximize-score-after-n-operations Hard
90 Bit Manipulation https://leetcode.com/problems/concatenation-of-consecutive-binary-numbers Medium
91 Bit Manipulation https://leetcode.com/problems/maximum-xor-for-each-query Medium
92 Bit Manipulation https://leetcode.com/problems/minimum-cost-to-connect-two-groups-of-points Hard
93 Bit Manipulation https://leetcode.com/problems/partition-array-into-two-arrays-to-minimize-sum-difference
Hard
94 Bit Manipulation https://leetcode.com/problems/transform-to-chessboard Hard
95 Bit Manipulation https://leetcode.com/problems/minimum-one-bit-operations-to-make-integers-zero Hard
96 Bit Manipulation https://leetcode.com/problems/count-subtrees-with-max-distance-between-citiesHard
97 Bit Manipulation https://leetcode.com/problems/find-xor-sum-of-all-pairs-bitwise-and Hard
98 Bit Manipulation https://leetcode.com/problems/find-kth-largest-xor-coordinate-value Medium
99 Bit Manipulation https://leetcode.com/problems/find-a-value-of-a-mysterious-function-closest-to-target
Hard
100 Bit Manipulation https://leetcode.com/problems/count-pairs-with-xor-in-a-range Hard
101 Bit Manipulation https://leetcode.com/problems/make-the-xor-of-all-segments-equal-to-zero Hard
102 Bit Manipulation https://leetcode.com/problems/circular-permutation-in-binary-representation Medium
103 Bit Manipulation https://leetcode.com/problems/triples-with-bitwise-and-equal-to-zero Hard
104 Bit Manipulation https://leetcode.com/problems/maximum-number-of-achievable-transfer-requestsHard
105 Bit Manipulation https://leetcode.com/problems/maximum-number-of-groups-getting-fresh-donutsHard
106 Bit Manipulation https://leetcode.com/problems/maximize-grid-happiness Hard
107 Bit Manipulation https://leetcode.com/problems/maximum-genetic-difference-query Hard
108 Bit Manipulation https://leetcode.com/problems/distribute-repeating-integers Hard
109 Bit Manipulation https://leetcode.com/problems/the-number-of-good-subsets Hard
110 Bit Manipulation https://leetcode.com/problems/count-number-of-maximum-bitwise-or-subsets Medium
111 Bit Manipulation https://leetcode.com/problems/minimum-incompatibility Hard
112 Bit Manipulation https://leetcode.com/problems/chalkboard-xor-game Hard
113 Bit Manipulation https://leetcode.com/problems/bulb-switcher-ii Medium
 Crack The Coding Interview - Dinesh Varyani
https://www.youtube.com/user/hubberspot?sub_confirmation=1

# Topic Question Difficulty

1 Stack https://leetcode.com/problems/trapping-rain-water Hard

2 Stack https://leetcode.com/problems/valid-parentheses Easy
3 Stack https://leetcode.com/problems/largest-rectangle-in-histogram Hard
4 Stack https://leetcode.com/problems/palindrome-linked-list Easy
5 Stack https://leetcode.com/problems/decode-string Medium
6 Stack https://leetcode.com/problems/min-stack Easy
7 Stack https://leetcode.com/problems/longest-valid-parentheses Hard
8 Stack https://leetcode.com/problems/binary-tree-inorder-traversal Easy
9 Stack https://leetcode.com/problems/flatten-binary-tree-to-linked-list Medium
10 Stack https://leetcode.com/problems/daily-temperatures Medium
11 Stack https://leetcode.com/problems/maximal-rectangle Hard
12 Stack https://leetcode.com/problems/reorder-list Medium
13 Stack https://leetcode.com/problems/shortest-unsorted-continuous-subarray Medium
14 Stack https://leetcode.com/problems/binary-search-tree-iterator Medium
15 Stack https://leetcode.com/problems/remove-k-digits Medium
16 Stack https://leetcode.com/problems/next-greater-element-ii Medium
17 Stack https://leetcode.com/problems/basic-calculator-ii Medium
18 Stack https://leetcode.com/problems/remove-duplicate-letters Medium
19 Stack https://leetcode.com/problems/binary-tree-postorder-traversal Easy
20 Stack https://leetcode.com/problems/binary-tree-preorder-traversal Easy
21 Stack https://leetcode.com/problems/backspace-string-compare Easy
22 Stack https://leetcode.com/problems/maximum-binary-tree Medium
23 Stack https://leetcode.com/problems/minimum-remove-to-make-valid-parentheses Medium
24 Stack https://leetcode.com/problems/basic-calculator Hard
25 Stack https://leetcode.com/problems/construct-binary-search-tree-from-preorder-traversal
Medium
26 Stack https://leetcode.com/problems/add-two-numbers-ii Medium
27 Stack https://leetcode.com/problems/valid-parenthesis-string Medium
28 Stack https://leetcode.com/problems/asteroid-collision Medium
29 Stack https://leetcode.com/problems/132-pattern Medium
30 Stack https://leetcode.com/problems/sum-of-subarray-minimums Medium
31 Stack https://leetcode.com/problems/flatten-nested-list-iterator Medium
32 Stack https://leetcode.com/problems/score-of-parentheses Medium
33 Stack https://leetcode.com/problems/minimum-cost-tree-from-leaf-values Medium
34 Stack https://leetcode.com/problems/implement-queue-using-stacks Easy
35 Stack https://leetcode.com/problems/remove-all-adjacent-duplicates-in-string Easy
36 Stack https://leetcode.com/problems/evaluate-reverse-polish-notation Medium
37 Stack https://leetcode.com/problems/maximum-frequency-stack Hard
38 Stack https://leetcode.com/problems/remove-all-adjacent-duplicates-in-string-ii Medium
39 Stack https://leetcode.com/problems/validate-stack-sequences Medium
40 Stack https://leetcode.com/problems/online-stock-span Medium
41 Stack https://leetcode.com/problems/increasing-order-search-tree Easy
42 Stack https://leetcode.com/problems/minimum-add-to-make-parentheses-valid Medium
43 Stack https://leetcode.com/problems/next-greater-node-in-linked-list Medium
44 Stack https://leetcode.com/problems/implement-stack-using-queues Easy
45 Stack https://leetcode.com/problems/next-greater-element-i Easy
46 Stack https://leetcode.com/problems/max-chunks-to-make-sorted Medium
47 Stack https://leetcode.com/problems/verify-preorder-serialization-of-a-binary-tree Medium
48 Stack https://leetcode.com/problems/n-ary-tree-preorder-traversal Easy
49 Stack https://leetcode.com/problems/exclusive-time-of-functions Medium
50 Stack https://leetcode.com/problems/n-ary-tree-postorder-traversal Easy
51 Stack https://leetcode.com/problems/count-submatrices-with-all-ones Medium
52 Stack https://leetcode.com/problems/smallest-subsequence-of-distinct-characters Medium
53 Stack https://leetcode.com/problems/odd-even-jump Hard
54 Stack https://leetcode.com/problems/create-maximum-number Hard
55 Stack https://leetcode.com/problems/car-fleet Medium
56 Stack https://leetcode.com/problems/simplify-path Medium
57 Stack https://leetcode.com/problems/remove-outermost-parentheses Easy
58 Stack https://leetcode.com/problems/reverse-substrings-between-each-pair-of-parentheses
Medium
59 Stack https://leetcode.com/problems/decoded-string-at-index Medium
60 Stack https://leetcode.com/problems/find-the-most-competitive-subsequence Medium
61 Stack https://leetcode.com/problems/maximum-width-ramp Medium
 62 Stack https://leetcode.com/problems/max-chunks-to-make-sorted-ii Hard
63 Stack https://leetcode.com/problems/design-browser-history Medium
64 Stack https://leetcode.com/problems/design-a-stack-with-increment-operation Medium
65 Stack https://leetcode.com/problems/baseball-game Easy
66 Stack https://leetcode.com/problems/longest-absolute-file-path Medium
67 Stack https://leetcode.com/problems/longest-well-performing-interval Medium
68 Stack https://leetcode.com/problems/shortest-subarray-to-be-removed-to-make-array-sorted
Medium
69 Stack https://leetcode.com/problems/number-of-atoms Hard
70 Stack https://leetcode.com/problems/final-prices-with-a-special-discount-in-a-shop Easy
71 Stack https://leetcode.com/problems/minimum-number-of-increments-on-subarrays-to-form-a-target-array
Hard
72 Stack https://leetcode.com/problems/maximum-nesting-depth-of-the-parentheses Easy
73 Stack https://leetcode.com/problems/maximum-subarray-min-product Medium
74 Stack https://leetcode.com/problems/make-the-string-great Easy
75 Stack https://leetcode.com/problems/number-of-students-unable-to-eat-lunch Easy
76 Stack https://leetcode.com/problems/minimum-deletions-to-make-string-balanced Medium
77 Stack https://leetcode.com/problems/minimum-insertions-to-balance-a-parentheses-string
Medium
78 Stack https://leetcode.com/problems/parsing-a-boolean-expression Hard
79 Stack https://leetcode.com/problems/number-of-visible-people-in-a-queue Hard
80 Stack https://leetcode.com/problems/car-fleet-ii Hard
81 Stack https://leetcode.com/problems/stamping-the-sequence Hard
82 Stack https://leetcode.com/problems/check-if-word-is-valid-after-substitutions Medium
83 Stack https://leetcode.com/problems/minimum-number-of-swaps-to-make-the-string-balanced
Medium
84 Stack https://leetcode.com/problems/maximum-score-of-a-good-subarray Hard
85 Stack https://leetcode.com/problems/the-number-of-weak-characters-in-the-game Medium
86 Stack https://leetcode.com/problems/build-an-array-with-stack-operations Easy
87 Stack https://leetcode.com/problems/crawler-log-folder Easy
88 Stack https://leetcode.com/problems/parse-lisp-expression Hard
89 Stack https://leetcode.com/problems/mini-parser Medium
90 Stack https://leetcode.com/problems/brace-expansion-ii Hard
91 Stack https://leetcode.com/problems/maximum-score-from-removing-substrings Medium
92 Stack https://leetcode.com/problems/dinner-plate-stacks Hard
93 Stack https://leetcode.com/problems/sum-of-subarray-ranges Medium
94 Stack https://leetcode.com/problems/maximum-nesting-depth-of-two-valid-parentheses-strings
Medium
95 Stack https://leetcode.com/problems/check-if-a-parentheses-string-can-be-valid Medium
96 Stack https://leetcode.com/problems/smallest-k-length-subsequence-with-occurrences-of-a-letter
Hard
97 Stack https://leetcode.com/problems/clumsy-factorial Medium
98 Stack https://leetcode.com/problems/minimum-cost-to-change-the-final-value-of-expression
Hard
99 Stack https://leetcode.com/problems/tag-validator Hard
100 Stack https://leetcode.com/problems/the-score-of-students-solving-math-expression Hard
101 Stack https://leetcode.com/problems/basic-calculator-iv Hard
 Crack The Coding Interview - Dinesh Varyani
https://www.youtube.com/user/hubberspot?sub_confirmation=1

# Topic Question Difficulty

1 Heap (Priority Queue) https://leetcode.com/problems/merge-k-sorted-lists Hard

2 Heap (Priority Queue) https://leetcode.com/problems/sliding-window-maximum Hard
3 Heap (Priority Queue) https://leetcode.com/problems/kth-largest-element-in-an-array Medium
4 Heap (Priority Queue) https://leetcode.com/problems/top-k-frequent-elements Medium
5 Heap (Priority Queue) https://leetcode.com/problems/find-median-from-data-stream Hard
6 Heap (Priority Queue) https://leetcode.com/problems/task-scheduler Medium
7 Heap (Priority Queue) https://leetcode.com/problems/kth-smallest-element-in-a-sorted-matrix Medium
8 Heap (Priority Queue) https://leetcode.com/problems/k-closest-points-to-origin Medium
9 Heap (Priority Queue) https://leetcode.com/problems/cheapest-flights-within-k-stops Medium
10 Heap (Priority Queue) https://leetcode.com/problems/reorganize-string Medium
11 Heap (Priority Queue) https://leetcode.com/problems/top-k-frequent-words Medium
12 Heap (Priority Queue) https://leetcode.com/problems/find-k-closest-elements Medium
13 Heap (Priority Queue) https://leetcode.com/problems/sort-characters-by-frequency Medium
14 Heap (Priority Queue) https://leetcode.com/problems/ugly-number-ii Medium
15 Heap (Priority Queue) https://leetcode.com/problems/the-skyline-problem Hard
16 Heap (Priority Queue) https://leetcode.com/problems/network-delay-time Medium
17 Heap (Priority Queue) https://leetcode.com/problems/find-k-pairs-with-smallest-sums Medium
18 Heap (Priority Queue) https://leetcode.com/problems/shortest-subarray-with-sum-at-least-k Hard
19 Heap (Priority Queue) https://leetcode.com/problems/trapping-rain-water-ii Hard
20 Heap (Priority Queue) https://leetcode.com/problems/minimum-number-of-refueling-stops Hard
21 Heap (Priority Queue) https://leetcode.com/problems/split-array-into-consecutive-subsequences Medium
22 Heap (Priority Queue) https://leetcode.com/problems/sliding-window-median Hard
23 Heap (Priority Queue) https://leetcode.com/problems/smallest-range-covering-elements-from-k-lists Hard
24 Heap (Priority Queue) https://leetcode.com/problems/last-stone-weight Easy
25 Heap (Priority Queue) https://leetcode.com/problems/longest-continuous-subarray-with-absolute-diff-less-than-or-equal-to-limit
Medium
26 Heap (Priority Queue) https://leetcode.com/problems/path-with-minimum-effort Medium
27 Heap (Priority Queue) https://leetcode.com/problems/kth-largest-element-in-a-stream Easy
28 Heap (Priority Queue) https://leetcode.com/problems/car-pooling Medium
29 Heap (Priority Queue) https://leetcode.com/problems/design-twitter Medium
30 Heap (Priority Queue) https://leetcode.com/problems/course-schedule-iii Hard
31 Heap (Priority Queue) https://leetcode.com/problems/swim-in-rising-water Hard
32 Heap (Priority Queue) https://leetcode.com/problems/sort-an-array Medium
33 Heap (Priority Queue) https://leetcode.com/problems/minimum-cost-to-hire-k-workers Hard
34 Heap (Priority Queue) https://leetcode.com/problems/maximum-number-of-events-that-can-be-attendedMedium
35 Heap (Priority Queue) https://leetcode.com/problems/furthest-building-you-can-reach Medium
36 Heap (Priority Queue) https://leetcode.com/problems/the-k-weakest-rows-in-a-matrix Easy
37 Heap (Priority Queue) https://leetcode.com/problems/super-ugly-number Medium
38 Heap (Priority Queue) https://leetcode.com/problems/jump-game-vi Medium
39 Heap (Priority Queue) https://leetcode.com/problems/reduce-array-size-to-the-half Medium
40 Heap (Priority Queue) https://leetcode.com/problems/maximum-performance-of-a-team Hard
41 Heap (Priority Queue) https://leetcode.com/problems/path-with-maximum-probability Medium
42 Heap (Priority Queue) https://leetcode.com/problems/minimum-cost-to-make-at-least-one-valid-path-in-a-grid
Hard
43 Heap (Priority Queue) https://leetcode.com/problems/longest-happy-string Medium
44 Heap (Priority Queue) https://leetcode.com/problems/avoid-flood-in-the-city Medium
45 Heap (Priority Queue) https://leetcode.com/problems/cut-off-trees-for-golf-event Hard
46 Heap (Priority Queue) https://leetcode.com/problems/distant-barcodes Medium
47 Heap (Priority Queue) https://leetcode.com/problems/find-the-kth-smallest-sum-of-a-matrix-with-sorted-rows
Hard
48 Heap (Priority Queue) https://leetcode.com/problems/maximum-product-of-two-elements-in-an-array Easy
49 Heap (Priority Queue) https://leetcode.com/problems/diagonal-traverse-ii Medium
50 Heap (Priority Queue) https://leetcode.com/problems/max-value-of-equation Hard
51 Heap (Priority Queue) https://leetcode.com/problems/ipo Hard
52 Heap (Priority Queue) https://leetcode.com/problems/constrained-subsequence-sum Hard
53 Heap (Priority Queue) https://leetcode.com/problems/k-th-smallest-prime-fraction Hard
54 Heap (Priority Queue) https://leetcode.com/problems/single-threaded-cpu Medium
55 Heap (Priority Queue) https://leetcode.com/problems/construct-target-array-with-multiple-sums Hard
56 Heap (Priority Queue) https://leetcode.com/problems/sell-diminishing-valued-colored-balls Medium
57 Heap (Priority Queue) https://leetcode.com/problems/minimum-moves-to-move-a-box-to-their-target-location
Hard
58 Heap (Priority Queue) https://leetcode.com/problems/car-fleet-ii Hard
59 Heap (Priority Queue) https://leetcode.com/problems/minimize-deviation-in-array Hard
60 Heap (Priority Queue) https://leetcode.com/problems/number-of-restricted-paths-from-first-to-last-nodeMedium
61 Heap (Priority Queue) https://leetcode.com/problems/pizza-with-3n-slices Hard
62 Heap (Priority Queue) https://leetcode.com/problems/reachable-nodes-in-subdivided-graph Hard
63 Heap (Priority Queue) https://leetcode.com/problems/process-tasks-using-servers Medium
64 Heap (Priority Queue) https://leetcode.com/problems/strong-password-checker Hard
65 Heap (Priority Queue) https://leetcode.com/problems/maximum-number-of-eaten-apples Medium
66 Heap (Priority Queue) https://leetcode.com/problems/maximum-average-pass-ratio Medium
67 Heap (Priority Queue) https://leetcode.com/problems/stone-game-vi Medium
68 Heap (Priority Queue) https://leetcode.com/problems/maximum-score-from-removing-stones Medium
69 Heap (Priority Queue) https://leetcode.com/problems/the-number-of-the-smallest-unoccupied-chair Medium
70 Heap (Priority Queue) https://leetcode.com/problems/minimum-interval-to-include-each-query Hard
71 Heap (Priority Queue) https://leetcode.com/problems/dinner-plate-stacks Hard
72 Heap (Priority Queue) https://leetcode.com/problems/relative-ranks Easy
73 Heap (Priority Queue) https://leetcode.com/problems/two-best-non-overlapping-events Medium
74 Heap (Priority Queue) https://leetcode.com/problems/find-the-kth-largest-integer-in-the-array Medium
75 Heap (Priority Queue) https://leetcode.com/problems/find-servers-that-handled-most-number-of-requests
Hard
76 Heap (Priority Queue) https://leetcode.com/problems/find-kth-largest-xor-coordinate-value Medium
77 Heap (Priority Queue) https://leetcode.com/problems/stock-price-fluctuation Medium
78 Heap (Priority Queue) https://leetcode.com/problems/remove-stones-to-minimize-the-total Medium
79 Heap (Priority Queue) https://leetcode.com/problems/seat-reservation-manager Medium
80 Heap (Priority Queue) https://leetcode.com/problems/find-subsequence-of-length-k-with-the-largest-sum
Easy
81 Heap (Priority Queue) https://leetcode.com/problems/delivering-boxes-from-storage-to-ports Hard
82 Heap (Priority Queue) https://leetcode.com/problems/finding-mk-average Hard
83 Heap (Priority Queue) https://leetcode.com/problems/number-of-orders-in-the-backlog Medium
84 Heap (Priority Queue) https://leetcode.com/problems/design-movie-rental-system Hard
85 Heap (Priority Queue) https://leetcode.com/problems/get-biggest-three-rhombus-sums-in-a-grid Medium
86 Heap (Priority Queue) https://leetcode.com/problems/sequentially-ordinal-rank-tracker Hard
 Crack The Coding Interview - Dinesh Varyani
https://www.youtube.com/user/hubberspot?sub_confirmation=1

# Topic Question Difficulty

1 Design https://leetcode.com/problems/lru-cache Medium

2 Design https://leetcode.com/problems/min-stack Easy
3 Design https://leetcode.com/problems/implement-trie-prefix-tree Medium
4 Design https://leetcode.com/problems/find-median-from-data-stream Hard
5 Design https://leetcode.com/problems/serialize-and-deserialize-binary-tree Hard
6 Design https://leetcode.com/problems/insert-delete-getrandom-o1 Medium
7 Design https://leetcode.com/problems/binary-search-tree-iterator Medium
8 Design https://leetcode.com/problems/design-add-and-search-words-data-structure Medium
9 Design https://leetcode.com/problems/flatten-nested-list-iterator Medium
10 Design https://leetcode.com/problems/lfu-cache Hard
11 Design https://leetcode.com/problems/implement-queue-using-stacks Easy
12 Design https://leetcode.com/problems/range-sum-query-mutable Medium
13 Design https://leetcode.com/problems/serialize-and-deserialize-bst Medium
14 Design https://leetcode.com/problems/maximum-frequency-stack Hard
15 Design https://leetcode.com/problems/range-sum-query-2d-immutable Medium
16 Design https://leetcode.com/problems/design-hashmap Easy
17 Design https://leetcode.com/problems/online-stock-span Medium
18 Design https://leetcode.com/problems/kth-largest-element-in-a-stream Easy
19 Design https://leetcode.com/problems/time-based-key-value-store Medium
20 Design https://leetcode.com/problems/design-twitter Medium
21 Design https://leetcode.com/problems/my-calendar-i Medium
22 Design https://leetcode.com/problems/range-sum-query-immutable Easy
23 Design https://leetcode.com/problems/implement-stack-using-queues Easy
24 Design https://leetcode.com/problems/insert-delete-getrandom-o1-duplicates-allowed Hard
25 Design https://leetcode.com/problems/design-circular-queue Medium
26 Design https://leetcode.com/problems/stream-of-characters Hard
27 Design https://leetcode.com/problems/snapshot-array Medium
28 Design https://leetcode.com/problems/design-linked-list Medium
29 Design https://leetcode.com/problems/map-sum-pairs Medium
30 Design https://leetcode.com/problems/encode-and-decode-tinyurl Medium
31 Design https://leetcode.com/problems/iterator-for-combination Medium
32 Design https://leetcode.com/problems/design-hashset Easy
33 Design https://leetcode.com/problems/design-underground-system Medium
34 Design https://leetcode.com/problems/my-calendar-ii Medium
35 Design https://leetcode.com/problems/all-oone-data-structure Hard
36 Design https://leetcode.com/problems/design-browser-history Medium
37 Design https://leetcode.com/problems/peeking-iterator Medium
38 Design https://leetcode.com/problems/prefix-and-suffix-search Hard
39 Design https://leetcode.com/problems/design-a-stack-with-increment-operation Medium
40 Design https://leetcode.com/problems/implement-magic-dictionary Medium
41 Design https://leetcode.com/problems/exam-room Medium
42 Design https://leetcode.com/problems/range-module Hard
43 Design https://leetcode.com/problems/kth-ancestor-of-a-tree-node Hard
44 Design https://leetcode.com/problems/product-of-the-last-k-numbers Medium
45 Design https://leetcode.com/problems/number-of-recent-calls Easy
46 Design https://leetcode.com/problems/complete-binary-tree-inserter Medium
47 Design https://leetcode.com/problems/my-calendar-iii Hard
48 Design https://leetcode.com/problems/online-election Medium
49 Design https://leetcode.com/problems/design-circular-deque Medium
50 Design https://leetcode.com/problems/data-stream-as-disjoint-intervals Hard
51 Design https://leetcode.com/problems/design-parking-system Easy
52 Design https://leetcode.com/problems/find-elements-in-a-contaminated-binary-tree Medium
53 Design https://leetcode.com/problems/rle-iterator Medium
54 Design https://leetcode.com/problems/online-majority-element-in-subarray Hard
55 Design https://leetcode.com/problems/design-front-middle-back-queue Medium
56 Design https://leetcode.com/problems/design-skiplist Hard
57 Design https://leetcode.com/problems/subrectangle-queries Medium
58 Design https://leetcode.com/problems/dinner-plate-stacks Hard
59 Design https://leetcode.com/problems/range-frequency-queries Medium
60 Design https://leetcode.com/problems/finding-pairs-with-a-certain-sum Medium
61 Design https://leetcode.com/problems/stock-price-fluctuation Medium
62 Design https://leetcode.com/problems/fancy-sequence Hard
63 Design https://leetcode.com/problems/seat-reservation-manager Medium
64 Design https://leetcode.com/problems/finding-mk-average Hard
65 Design https://leetcode.com/problems/detect-squares Medium
66 Design https://leetcode.com/problems/design-an-ordered-stream Easy
67 Design https://leetcode.com/problems/operations-on-tree Medium
68 Design https://leetcode.com/problems/throne-inheritance Medium
69 Design https://leetcode.com/problems/design-authentication-manager Medium
70 Design https://leetcode.com/problems/design-movie-rental-system Hard
71 Design https://leetcode.com/problems/apply-discount-every-n-orders Medium
72 Design https://leetcode.com/problems/walking-robot-simulation-ii Medium
73 Design https://leetcode.com/problems/tweet-counts-per-frequency Medium
74 Design https://leetcode.com/problems/sequentially-ordinal-rank-tracker Hard
75 Design https://leetcode.com/problems/simple-bank-system Medium
 Crack The Coding Interview - Dinesh Varyani
https://www.youtube.com/user/hubberspot?sub_confirmation=1

# Topic Question Difficulty

1 Simulation https://leetcode.com/problems/spiral-matrix Medium

2 Simulation https://leetcode.com/problems/add-binary Easy
3 Simulation https://leetcode.com/problems/multiply-strings Medium
4 Simulation https://leetcode.com/problems/game-of-life Medium
5 Simulation https://leetcode.com/problems/backspace-string-compare Easy
6 Simulation https://leetcode.com/problems/add-strings Easy
7 Simulation https://leetcode.com/problems/spiral-matrix-ii Medium
8 Simulation https://leetcode.com/problems/validate-stack-sequences Medium
9 Simulation https://leetcode.com/problems/robot-bounded-in-circle Medium
10 Simulation https://leetcode.com/problems/diagonal-traverse Medium
11 Simulation https://leetcode.com/problems/flipping-an-image Easy
12 Simulation https://leetcode.com/problems/car-pooling Medium
13 Simulation https://leetcode.com/problems/reshape-the-matrix Easy
14 Simulation https://leetcode.com/problems/reveal-cards-in-increasing-order Medium
15 Simulation https://leetcode.com/problems/robot-return-to-origin Easy
16 Simulation https://leetcode.com/problems/add-digits Easy
17 Simulation https://leetcode.com/problems/text-justification Hard
18 Simulation https://leetcode.com/problems/transpose-matrix Easy
19 Simulation https://leetcode.com/problems/baseball-game Easy
20 Simulation https://leetcode.com/problems/create-target-array-in-the-given-order Easy
21 Simulation https://leetcode.com/problems/find-the-winner-of-the-circular-game Medium
22 Simulation https://leetcode.com/problems/build-array-from-permutation Easy
23 Simulation https://leetcode.com/problems/find-winner-on-a-tic-tac-toe-game Easy
24 Simulation https://leetcode.com/problems/distribute-candies-to-people Easy
25 Simulation https://leetcode.com/problems/cells-with-odd-values-in-a-matrix Easy
26 Simulation https://leetcode.com/problems/sum-of-even-numbers-after-queries Medium
27 Simulation https://leetcode.com/problems/where-will-the-ball-fall Medium
28 Simulation https://leetcode.com/problems/number-of-students-unable-to-eat-lunch Easy
29 Simulation https://leetcode.com/problems/queens-that-can-attack-the-king Medium
30 Simulation https://leetcode.com/problems/water-bottles Easy
31 Simulation https://leetcode.com/problems/design-parking-system Easy
32 Simulation https://leetcode.com/problems/count-of-matches-in-tournament Easy
33 Simulation https://leetcode.com/problems/complex-number-multiplication Medium
34 Simulation https://leetcode.com/problems/spiral-matrix-iii Medium
35 Simulation https://leetcode.com/problems/shift-2d-grid Easy
36 Simulation https://leetcode.com/problems/find-the-winner-of-an-array-game Medium
37 Simulation https://leetcode.com/problems/find-latest-group-of-size-m Medium
38 Simulation https://leetcode.com/problems/build-an-array-with-stack-operations Easy
39 Simulation https://leetcode.com/problems/available-captures-for-rook Easy
40 Simulation https://leetcode.com/problems/print-words-vertically Medium
41 Simulation https://leetcode.com/problems/solve-the-equation Medium
42 Simulation https://leetcode.com/problems/concatenation-of-consecutive-binary-numbers Medium
43 Simulation https://leetcode.com/problems/last-moment-before-all-ants-fall-out-of-a-plank Medium
44 Simulation https://leetcode.com/problems/queries-on-a-permutation-with-key Medium
45 Simulation https://leetcode.com/problems/get-maximum-in-generated-array Easy
46 Simulation https://leetcode.com/problems/average-waiting-time Medium
47 Simulation https://leetcode.com/problems/fraction-addition-and-subtraction Medium
48 Simulation https://leetcode.com/problems/final-value-of-variable-after-performing-operationsEasy
49 Simulation https://leetcode.com/problems/teemo-attacking Easy
50 Simulation https://leetcode.com/problems/time-needed-to-buy-tickets Easy
51 Simulation https://leetcode.com/problems/contain-virus Hard
52 Simulation https://leetcode.com/problems/find-the-student-that-will-replace-the-chalk Medium
53 Simulation https://leetcode.com/problems/minimum-number-of-operations-to-reinitialize-a-permutation
Medium
54 Simulation https://leetcode.com/problems/sum-of-digits-of-string-after-convert Easy
55 Simulation https://leetcode.com/problems/most-visited-sector-in-a-circular-track Easy
56 Simulation https://leetcode.com/problems/find-missing-observations Medium
57 Simulation https://leetcode.com/problems/convert-1d-array-into-2d-array Easy
58 Simulation https://leetcode.com/problems/clumsy-factorial Medium
59 Simulation https://leetcode.com/problems/adding-spaces-to-a-string Medium
60 Simulation https://leetcode.com/problems/count-unhappy-friends Medium
61 Simulation https://leetcode.com/problems/number-of-orders-in-the-backlog Medium
62 Simulation https://leetcode.com/problems/cyclically-rotating-a-grid Medium
63 Simulation https://leetcode.com/problems/execution-of-all-suffix-instructions-staying-in-a-grid
Medium
64 Simulation https://leetcode.com/problems/incremental-memory-leak Medium
65 Simulation https://leetcode.com/problems/decode-the-slanted-ciphertext Medium
66 Simulation https://leetcode.com/problems/walking-robot-simulation-ii Medium
67 Simulation https://leetcode.com/problems/fizz-buzz Easy
68 Simulation https://leetcode.com/problems/simple-bank-system Medium
69 Simulation https://leetcode.com/problems/watering-plants-ii Medium
70 Simulation https://leetcode.com/problems/maximum-profit-of-operating-a-centennial-wheel Medium
71 Simulation https://leetcode.com/problems/walking-robot-simulation Medium
72 Simulation https://leetcode.com/problems/number-of-valid-move-combinations-on-chessboard Hard
 Crack The Coding Interview - Dinesh Varyani
https://www.youtube.com/user/hubberspot?sub_confirmation=1

# Topic Question Difficulty

1 Backtracking https://leetcode.com/problems/generate-parentheses Medium

2 Backtracking https://leetcode.com/problems/permutations Medium
3 Backtracking https://leetcode.com/problems/combination-sum Medium
4 Backtracking https://leetcode.com/problems/letter-combinations-of-a-phone-number Medium
5 Backtracking https://leetcode.com/problems/word-search Medium
6 Backtracking https://leetcode.com/problems/subsets Medium
7 Backtracking https://leetcode.com/problems/target-sum Medium
8 Backtracking https://leetcode.com/problems/word-search-ii Hard
9 Backtracking https://leetcode.com/problems/palindrome-partitioning Medium
10 Backtracking https://leetcode.com/problems/n-queens Hard
11 Backtracking https://leetcode.com/problems/unique-binary-search-trees-ii Medium
12 Backtracking https://leetcode.com/problems/sudoku-solver Hard
13 Backtracking https://leetcode.com/problems/remove-invalid-parentheses Hard
14 Backtracking https://leetcode.com/problems/partition-to-k-equal-sum-subsets Medium
15 Backtracking https://leetcode.com/problems/permutations-ii Medium
16 Backtracking https://leetcode.com/problems/word-break-ii Hard
17 Backtracking https://leetcode.com/problems/combination-sum-ii Medium
18 Backtracking https://leetcode.com/problems/path-sum-ii Medium
19 Backtracking https://leetcode.com/problems/subsets-ii Medium
20 Backtracking https://leetcode.com/problems/combinations Medium
21 Backtracking https://leetcode.com/problems/all-paths-from-source-to-target Medium
22 Backtracking https://leetcode.com/problems/word-ladder-ii Hard
23 Backtracking https://leetcode.com/problems/letter-case-permutation Medium
24 Backtracking https://leetcode.com/problems/unique-paths-iii Hard
25 Backtracking https://leetcode.com/problems/combination-sum-iii Medium
26 Backtracking https://leetcode.com/problems/restore-ip-addresses Medium
27 Backtracking https://leetcode.com/problems/expression-add-operators Hard
28 Backtracking https://leetcode.com/problems/beautiful-arrangement Medium
29 Backtracking https://leetcode.com/problems/path-with-maximum-gold Medium
30 Backtracking https://leetcode.com/problems/maximum-length-of-a-concatenated-string-with-unique-characters
Medium
31 Backtracking https://leetcode.com/problems/letter-tile-possibilities Medium
32 Backtracking https://leetcode.com/problems/matchsticks-to-square Medium
33 Backtracking https://leetcode.com/problems/n-queens-ii Hard
34 Backtracking https://leetcode.com/problems/increasing-subsequences Medium
35 Backtracking https://leetcode.com/problems/gray-code Medium
36 Backtracking https://leetcode.com/problems/24-game Hard
37 Backtracking https://leetcode.com/problems/iterator-for-combination Medium
38 Backtracking https://leetcode.com/problems/shopping-offers Medium
39 Backtracking https://leetcode.com/problems/binary-watch Easy
40 Backtracking https://leetcode.com/problems/numbers-with-same-consecutive-differences Medium
41 Backtracking https://leetcode.com/problems/count-numbers-with-unique-digits Medium
42 Backtracking https://leetcode.com/problems/split-array-into-fibonacci-sequence Medium
43 Backtracking https://leetcode.com/problems/additive-number Medium
44 Backtracking https://leetcode.com/problems/stickers-to-spell-word Hard
45 Backtracking https://leetcode.com/problems/number-of-squareful-arrays Hard
46 Backtracking https://leetcode.com/problems/the-k-th-lexicographical-string-of-all-happy-strings-of-length-n
Medium
47 Backtracking https://leetcode.com/problems/sum-of-all-subset-xor-totals Easy
48 Backtracking https://leetcode.com/problems/maximum-score-words-formed-by-letters Hard
49 Backtracking https://leetcode.com/problems/split-a-string-into-the-max-number-of-unique-substrings
Medium
50 Backtracking https://leetcode.com/problems/find-minimum-time-to-finish-all-jobs Hard
51 Backtracking https://leetcode.com/problems/tiling-a-rectangle-with-the-fewest-squares Hard
52 Backtracking https://leetcode.com/problems/minimum-number-of-work-sessions-to-finish-the-tasksMedium
53 Backtracking https://leetcode.com/problems/find-unique-binary-string Medium
54 Backtracking https://leetcode.com/problems/maximum-compatibility-score-sum Medium
55 Backtracking https://leetcode.com/problems/construct-the-lexicographically-largest-valid-sequence
Medium
56 Backtracking https://leetcode.com/problems/brace-expansion-ii Hard
57 Backtracking https://leetcode.com/problems/closest-dessert-cost Medium
58 Backtracking https://leetcode.com/problems/maximum-product-of-the-length-of-two-palindromic-subsequences
Medium
59 Backtracking https://leetcode.com/problems/maximize-score-after-n-operations Hard
60 Backtracking https://leetcode.com/problems/verbal-arithmetic-puzzle Hard
61 Backtracking https://leetcode.com/problems/splitting-a-string-into-descending-consecutive-values
Medium
62 Backtracking https://leetcode.com/problems/ambiguous-coordinates Medium
63 Backtracking https://leetcode.com/problems/circular-permutation-in-binary-representation Medium
64 Backtracking https://leetcode.com/problems/probability-of-a-two-boxes-having-the-same-number-of-distinct-balls
Hard
65 Backtracking https://leetcode.com/problems/distribute-repeating-integers Hard
66 Backtracking https://leetcode.com/problems/maximum-path-quality-of-a-graph Hard
67 Backtracking https://leetcode.com/problems/count-number-of-maximum-bitwise-or-subsets Medium
68 Backtracking https://leetcode.com/problems/longest-subsequence-repeated-k-times Hard
69 Backtracking https://leetcode.com/problems/next-greater-numerically-balanced-number Medium
70 Backtracking https://leetcode.com/problems/number-of-valid-move-combinations-on-chessboard
Hard
 Crack The Coding Interview - Dinesh Varyani
https://www.youtube.com/user/hubberspot?sub_confirmation=1

# Topic Question Difficulty

1 Graph https://leetcode.com/problems/course-schedule Medium

2 Graph https://leetcode.com/problems/course-schedule-ii Medium
3 Graph https://leetcode.com/problems/minimum-height-trees Medium
4 Graph https://leetcode.com/problems/longest-increasing-path-in-a-matrix Hard
5 Graph https://leetcode.com/problems/evaluate-division Medium
6 Graph https://leetcode.com/problems/clone-graph Medium
7 Graph https://leetcode.com/problems/number-of-provinces Medium
8 Graph https://leetcode.com/problems/cheapest-flights-within-k-stops Medium
9 Graph https://leetcode.com/problems/is-graph-bipartite Medium
10 Graph https://leetcode.com/problems/reconstruct-itinerary Hard
11 Graph https://leetcode.com/problems/network-delay-time Medium
12 Graph https://leetcode.com/problems/all-paths-from-source-to-target Medium
13 Graph https://leetcode.com/problems/critical-connections-in-a-network Hard
14 Graph https://leetcode.com/problems/redundant-connection Medium
15 Graph https://leetcode.com/problems/find-the-town-judge Easy
16 Graph https://leetcode.com/problems/keys-and-rooms Medium
17 Graph https://leetcode.com/problems/sum-of-distances-in-tree Hard
18 Graph https://leetcode.com/problems/most-stones-removed-with-same-row-or-column Medium
19 Graph https://leetcode.com/problems/possible-bipartition Medium
20 Graph https://leetcode.com/problems/regions-cut-by-slashes Medium
21 Graph https://leetcode.com/problems/find-eventual-safe-states Medium
22 Graph https://leetcode.com/problems/number-of-operations-to-make-network-connected Medium
23 Graph https://leetcode.com/problems/couples-holding-hands Hard
24 Graph https://leetcode.com/problems/redundant-connection-ii Hard
25 Graph https://leetcode.com/problems/satisfiability-of-equality-equations Medium
26 Graph https://leetcode.com/problems/shortest-path-visiting-all-nodes Hard
27 Graph https://leetcode.com/problems/reorder-routes-to-make-all-paths-lead-to-the-city-zero
Medium
28 Graph https://leetcode.com/problems/minimum-number-of-vertices-to-reach-all-nodes Medium
29 Graph https://leetcode.com/problems/shortest-path-with-alternating-colors Medium
30 Graph https://leetcode.com/problems/path-with-maximum-probability Medium
31 Graph https://leetcode.com/problems/find-the-city-with-the-smallest-number-of-neighbors-at-a-threshold-distance
Medium
32 Graph https://leetcode.com/problems/minimum-cost-to-make-at-least-one-valid-path-in-a-grid
Hard
33 Graph https://leetcode.com/problems/flower-planting-with-no-adjacent Medium
34 Graph https://leetcode.com/problems/validate-binary-tree-nodes Medium
35 Graph https://leetcode.com/problems/course-schedule-iv Medium
36 Graph https://leetcode.com/problems/number-of-ways-to-arrive-at-destination Medium
37 Graph https://leetcode.com/problems/cat-and-mouse Hard
38 Graph https://leetcode.com/problems/rank-transform-of-a-matrix Hard
39 Graph https://leetcode.com/problems/sort-items-by-groups-respecting-dependencies Hard
40 Graph https://leetcode.com/problems/maximal-network-rank Medium
41 Graph https://leetcode.com/problems/loud-and-rich Medium
42 Graph https://leetcode.com/problems/parallel-courses-ii Hard
43 Graph https://leetcode.com/problems/remove-max-number-of-edges-to-keep-graph-fully-traversable
Hard
44 Graph https://leetcode.com/problems/find-if-path-exists-in-graph Easy
45 Graph https://leetcode.com/problems/number-of-restricted-paths-from-first-to-last-nodeMedium
46 Graph https://leetcode.com/problems/reachable-nodes-in-subdivided-graph Hard
47 Graph https://leetcode.com/problems/checking-existence-of-edge-length-limited-paths Hard
48 Graph https://leetcode.com/problems/find-critical-and-pseudo-critical-edges-in-minimum-spanning-tree
Hard
49 Graph https://leetcode.com/problems/largest-color-value-in-a-directed-graph Hard
50 Graph https://leetcode.com/problems/minimum-cost-to-reach-destination-in-time Hard
51 Graph https://leetcode.com/problems/find-center-of-star-graph Easy
52 Graph https://leetcode.com/problems/frog-position-after-t-seconds Hard
53 Graph https://leetcode.com/problems/find-all-people-with-secret Hard
54 Graph https://leetcode.com/problems/strange-printer-ii Hard
55 Graph https://leetcode.com/problems/find-all-possible-recipes-from-given-supplies Medium
56 Graph https://leetcode.com/problems/second-minimum-time-to-reach-destination Hard
57 Graph https://leetcode.com/problems/process-restricted-friend-requests Hard
58 Graph https://leetcode.com/problems/parallel-courses-iii Hard
59 Graph https://leetcode.com/problems/count-ways-to-build-rooms-in-an-ant-colony Hard
60 Graph https://leetcode.com/problems/detonate-the-maximum-bombs Medium
61 Graph https://leetcode.com/problems/the-time-when-the-network-becomes-idle Medium
62 Graph https://leetcode.com/problems/count-pairs-of-nodes Hard
63 Graph https://leetcode.com/problems/valid-arrangement-of-pairs Hard
64 Graph https://leetcode.com/problems/maximum-path-quality-of-a-graph Hard
65 Graph https://leetcode.com/problems/minimum-degree-of-a-connected-trio-in-a-graph Hard
66 Graph https://leetcode.com/problems/cat-and-mouse-ii Hard
67 Graph https://leetcode.com/problems/cracking-the-safe Hard
68 Graph https://leetcode.com/problems/number-of-ways-to-reconstruct-a-tree Hard
 Crack The Coding Interview - Dinesh Varyani
https://www.youtube.com/user/hubberspot?sub_confirmation=1

# Topic Question Difficulty

1 Prefix Sum https://leetcode.com/problems/product-of-array-except-self Medium

2 Prefix Sum https://leetcode.com/problems/subarray-sum-equals-k Medium
3 Prefix Sum https://leetcode.com/problems/minimum-size-subarray-sum Medium
4 Prefix Sum https://leetcode.com/problems/max-consecutive-ones-iii Medium
5 Prefix Sum https://leetcode.com/problems/contiguous-array Medium
6 Prefix Sum https://leetcode.com/problems/find-pivot-index Easy
7 Prefix Sum https://leetcode.com/problems/shortest-subarray-with-sum-at-least-k Hard
8 Prefix Sum https://leetcode.com/problems/maximum-points-you-can-obtain-from-cards Medium
9 Prefix Sum https://leetcode.com/problems/subarray-sums-divisible-by-k Medium
10 Prefix Sum https://leetcode.com/problems/range-sum-query-2d-immutable Medium
11 Prefix Sum https://leetcode.com/problems/running-sum-of-1d-array Easy
12 Prefix Sum https://leetcode.com/problems/car-pooling Medium
13 Prefix Sum https://leetcode.com/problems/range-sum-query-immutable Easy
14 Prefix Sum https://leetcode.com/problems/sum-of-all-odd-length-subarrays Easy
15 Prefix Sum https://leetcode.com/problems/matrix-block-sum Medium
16 Prefix Sum https://leetcode.com/problems/number-of-submatrices-that-sum-to-target Hard
17 Prefix Sum https://leetcode.com/problems/minimum-operations-to-reduce-x-to-zero Medium
18 Prefix Sum https://leetcode.com/problems/continuous-subarray-sum Medium
19 Prefix Sum https://leetcode.com/problems/binary-subarrays-with-sum Medium
20 Prefix Sum https://leetcode.com/problems/find-the-longest-substring-containing-vowels-in-even-counts
Medium
21 Prefix Sum https://leetcode.com/problems/minimum-value-to-get-positive-step-by-step-sum Easy
22 Prefix Sum https://leetcode.com/problems/corporate-flight-bookings Medium
23 Prefix Sum https://leetcode.com/problems/frequency-of-the-most-frequent-element Medium
24 Prefix Sum https://leetcode.com/problems/longest-well-performing-interval Medium
25 Prefix Sum https://leetcode.com/problems/count-triplets-that-can-form-two-arrays-of-equal-xor
Medium
26 Prefix Sum https://leetcode.com/problems/xor-queries-of-a-subarray Medium
27 Prefix Sum https://leetcode.com/problems/make-sum-divisible-by-p Medium
28 Prefix Sum https://leetcode.com/problems/maximum-side-length-of-a-square-with-sum-less-than-or-equal-to-threshold
Medium
29 Prefix Sum https://leetcode.com/problems/minimum-number-of-k-consecutive-bit-flips Hard
30 Prefix Sum https://leetcode.com/problems/jump-game-vii Medium
31 Prefix Sum https://leetcode.com/problems/maximum-number-of-non-overlapping-subarrays-with-sum-equals-target
Medium
32 Prefix Sum https://leetcode.com/problems/number-of-sub-arrays-with-odd-sum Medium
33 Prefix Sum https://leetcode.com/problems/maximum-subarray-min-product Medium
34 Prefix Sum https://leetcode.com/problems/ways-to-split-array-into-three-subarrays Medium
35 Prefix Sum https://leetcode.com/problems/find-the-highest-altitude Easy
36 Prefix Sum https://leetcode.com/problems/sum-of-absolute-differences-in-a-sorted-array Medium
37 Prefix Sum https://leetcode.com/problems/get-equal-substrings-within-budget Medium
38 Prefix Sum https://leetcode.com/problems/number-of-wonderful-substrings Medium
39 Prefix Sum https://leetcode.com/problems/can-make-palindrome-from-substring Medium
40 Prefix Sum https://leetcode.com/problems/maximum-sum-obtained-of-any-permutation Medium
41 Prefix Sum https://leetcode.com/problems/minimum-moves-to-make-array-complementary Medium
42 Prefix Sum https://leetcode.com/problems/unique-length-3-palindromic-subsequences Medium
43 Prefix Sum https://leetcode.com/problems/random-point-in-non-overlapping-rectangles Medium
44 Prefix Sum https://leetcode.com/problems/minimum-adjacent-swaps-for-k-consecutive-onesHard
45 Prefix Sum https://leetcode.com/problems/grid-game Medium
46 Prefix Sum https://leetcode.com/problems/intervals-between-identical-elements Medium
47 Prefix Sum https://leetcode.com/problems/smallest-rotation-with-highest-score Hard
48 Prefix Sum https://leetcode.com/problems/maximum-xor-for-each-query Medium
49 Prefix Sum https://leetcode.com/problems/maximize-the-confusion-of-an-exam Medium
50 Prefix Sum https://leetcode.com/problems/random-pick-with-weight Medium
51 Prefix Sum https://leetcode.com/problems/sum-of-floored-pairs Hard
52 Prefix Sum https://leetcode.com/problems/find-the-middle-index-in-array Easy
53 Prefix Sum https://leetcode.com/problems/plates-between-candles Medium
54 Prefix Sum https://leetcode.com/problems/find-kth-largest-xor-coordinate-value Medium
55 Prefix Sum https://leetcode.com/problems/describe-the-painting Medium
56 Prefix Sum https://leetcode.com/problems/stone-game-viii Hard
57 Prefix Sum https://leetcode.com/problems/maximum-number-of-ways-to-partition-an-array Hard
58 Prefix Sum https://leetcode.com/problems/minimum-space-wasted-from-packaging Hard
59 Prefix Sum https://leetcode.com/problems/check-if-all-the-integers-in-a-range-are-covered Easy
60 Prefix Sum https://leetcode.com/problems/change-minimum-characters-to-satisfy-one-of-three-conditions
Medium
61 Prefix Sum https://leetcode.com/problems/maximum-fruits-harvested-after-at-most-k-steps Hard
62 Prefix Sum https://leetcode.com/problems/find-good-days-to-rob-the-bank Medium
63 Prefix Sum https://leetcode.com/problems/find-the-student-that-will-replace-the-chalk Medium
64 Prefix Sum https://leetcode.com/problems/largest-magic-square Medium
65 Prefix Sum https://leetcode.com/problems/get-biggest-three-rhombus-sums-in-a-grid Medium
66 Prefix Sum https://leetcode.com/problems/can-you-eat-your-favorite-candy-on-your-favorite-day
Medium
 Crack The Coding Interview - Dinesh Varyani
https://www.youtube.com/user/hubberspot?sub_confirmation=1

# Topic Question Difficulty

1 Counting https://leetcode.com/problems/majority-element Easy

2 Counting https://leetcode.com/problems/top-k-frequent-elements Medium
3 Counting https://leetcode.com/problems/task-scheduler Medium
4 Counting https://leetcode.com/problems/first-unique-character-in-a-string Easy
5 Counting https://leetcode.com/problems/reorganize-string Medium
6 Counting https://leetcode.com/problems/majority-element-ii Medium
7 Counting https://leetcode.com/problems/top-k-frequent-words Medium
8 Counting https://leetcode.com/problems/sort-characters-by-frequency Medium
9 Counting https://leetcode.com/problems/pairs-of-songs-with-total-durations-divisible-by-60Medium
10 Counting https://leetcode.com/problems/how-many-numbers-are-smaller-than-the-current-number
Easy
11 Counting https://leetcode.com/problems/subarrays-with-k-different-integers Hard
12 Counting https://leetcode.com/problems/number-of-good-pairs Easy
13 Counting https://leetcode.com/problems/split-a-string-in-balanced-strings Easy
14 Counting https://leetcode.com/problems/ransom-note Easy
15 Counting https://leetcode.com/problems/bulls-and-cows Medium
16 Counting https://leetcode.com/problems/x-of-a-kind-in-a-deck-of-cards Easy
17 Counting https://leetcode.com/problems/subdomain-visit-count Medium
18 Counting https://leetcode.com/problems/minimum-increment-to-make-array-unique Medium
19 Counting https://leetcode.com/problems/maximum-number-of-balloons Easy
20 Counting https://leetcode.com/problems/3sum-with-multiplicity Medium
21 Counting https://leetcode.com/problems/sort-integers-by-the-number-of-1-bits Easy
22 Counting https://leetcode.com/problems/count-servers-that-communicate Medium
23 Counting https://leetcode.com/problems/distant-barcodes Medium
24 Counting https://leetcode.com/problems/check-if-array-pairs-are-divisible-by-k Medium
25 Counting https://leetcode.com/problems/least-number-of-unique-integers-after-k-removalsMedium
26 Counting https://leetcode.com/problems/rank-teams-by-votes Medium
27 Counting https://leetcode.com/problems/construct-k-palindrome-strings Medium
28 Counting https://leetcode.com/problems/sum-of-unique-elements Easy
29 Counting https://leetcode.com/problems/minimum-number-of-frogs-croaking Medium
30 Counting https://leetcode.com/problems/reordered-power-of-2 Medium
31 Counting https://leetcode.com/problems/find-lucky-integer-in-an-array Easy
32 Counting https://leetcode.com/problems/design-parking-system Easy
33 Counting https://leetcode.com/problems/rle-iterator Medium
34 Counting https://leetcode.com/problems/increasing-decreasing-string Easy
35 Counting https://leetcode.com/problems/number-of-equivalent-domino-pairs Easy
36 Counting https://leetcode.com/problems/determine-if-string-halves-are-alike Easy
37 Counting https://leetcode.com/problems/equal-sum-arrays-with-minimum-number-of-operations Medium
38 Counting https://leetcode.com/problems/maximum-population-year Easy
39 Counting https://leetcode.com/problems/substrings-of-size-three-with-distinct-characters Easy
40 Counting https://leetcode.com/problems/largest-color-value-in-a-directed-graph Hard
41 Counting https://leetcode.com/problems/count-nice-pairs-in-an-array Medium
42 Counting https://leetcode.com/problems/maximum-number-of-balls-in-a-box Easy
43 Counting https://leetcode.com/problems/check-if-one-string-swap-can-make-strings-equal Easy
44 Counting https://leetcode.com/problems/sum-of-beauty-of-all-substrings Medium
45 Counting https://leetcode.com/problems/largest-values-from-labels Medium
46 Counting https://leetcode.com/problems/check-if-all-characters-have-equal-number-of-occurrences
Easy
47 Counting https://leetcode.com/problems/number-of-different-subsequences-gcds Hard
48 Counting https://leetcode.com/problems/redistribute-characters-to-make-all-strings-equal Easy
49 Counting https://leetcode.com/problems/maximum-number-of-ways-to-partition-an-array Hard
50 Counting https://leetcode.com/problems/change-minimum-characters-to-satisfy-one-of-three-conditions
Medium
51 Counting https://leetcode.com/problems/number-of-pairs-of-interchangeable-rectangles Medium
52 Counting https://leetcode.com/problems/detect-squares Medium
53 Counting https://leetcode.com/problems/kth-distinct-string-in-an-array Easy
54 Counting https://leetcode.com/problems/count-common-words-with-one-occurrence Easy
55 Counting https://leetcode.com/problems/longest-subsequence-repeated-k-times Hard
56 Counting https://leetcode.com/problems/check-whether-two-strings-are-almost-equivalent Easy
57 Counting https://leetcode.com/problems/stone-game-ix Medium
 Crack The Coding Interview - Dinesh Varyani
https://www.youtube.com/user/hubberspot?sub_confirmation=1

# Topic Question Difficulty

1 Sliding Window https://leetcode.com/problems/longest-substring-without-repeating-characters Medium

2 Sliding Window https://leetcode.com/problems/minimum-window-substring Hard
3 Sliding Window https://leetcode.com/problems/sliding-window-maximum Hard
4 Sliding Window https://leetcode.com/problems/find-all-anagrams-in-a-string Medium
5 Sliding Window https://leetcode.com/problems/minimum-size-subarray-sum Medium
6 Sliding Window https://leetcode.com/problems/permutation-in-string Medium
7 Sliding Window https://leetcode.com/problems/max-consecutive-ones-iii Medium
8 Sliding Window https://leetcode.com/problems/longest-repeating-character-replacement Medium
9 Sliding Window https://leetcode.com/problems/longest-substring-with-at-least-k-repeating-characters
Medium
10 Sliding Window https://leetcode.com/problems/maximum-length-of-repeated-subarray Medium
11 Sliding Window https://leetcode.com/problems/subarray-product-less-than-k Medium
12 Sliding Window https://leetcode.com/problems/subarrays-with-k-different-integers Hard
13 Sliding Window https://leetcode.com/problems/shortest-subarray-with-sum-at-least-k Hard
14 Sliding Window https://leetcode.com/problems/maximum-points-you-can-obtain-from-cards Medium
15 Sliding Window https://leetcode.com/problems/contains-duplicate-iii Medium
16 Sliding Window https://leetcode.com/problems/contains-duplicate-ii Easy
17 Sliding Window https://leetcode.com/problems/sliding-window-median Hard
18 Sliding Window https://leetcode.com/problems/smallest-range-covering-elements-from-k-lists Hard
19 Sliding Window https://leetcode.com/problems/longest-continuous-subarray-with-absolute-diff-less-than-or-equal-to-limit
Medium
20 Sliding Window https://leetcode.com/problems/repeated-dna-sequences Medium
21 Sliding Window https://leetcode.com/problems/substring-with-concatenation-of-all-words Hard
22 Sliding Window https://leetcode.com/problems/longest-duplicate-substring Hard
23 Sliding Window https://leetcode.com/problems/maximum-sum-of-two-non-overlapping-subarraysMedium
24 Sliding Window https://leetcode.com/problems/count-number-of-nice-subarrays Medium
25 Sliding Window https://leetcode.com/problems/maximum-average-subarray-i Easy
26 Sliding Window https://leetcode.com/problems/minimum-operations-to-reduce-x-to-zero Medium
27 Sliding Window https://leetcode.com/problems/number-of-substrings-containing-all-three-characters
Medium
28 Sliding Window https://leetcode.com/problems/longest-turbulent-subarray Medium
29 Sliding Window https://leetcode.com/problems/binary-subarrays-with-sum Medium
30 Sliding Window https://leetcode.com/problems/jump-game-vi Medium
31 Sliding Window https://leetcode.com/problems/find-two-non-overlapping-sub-arrays-each-with-target-sum
Medium
32 Sliding Window https://leetcode.com/problems/grumpy-bookstore-owner Medium
33 Sliding Window https://leetcode.com/problems/new-21-game Medium
34 Sliding Window https://leetcode.com/problems/frequency-of-the-most-frequent-element Medium
35 Sliding Window https://leetcode.com/problems/max-value-of-equation Hard
36 Sliding Window https://leetcode.com/problems/maximum-erasure-value Medium
37 Sliding Window https://leetcode.com/problems/longest-subarray-of-1s-after-deleting-one-elementMedium
38 Sliding Window https://leetcode.com/problems/minimum-number-of-k-consecutive-bit-flips Hard
39 Sliding Window https://leetcode.com/problems/constrained-subsequence-sum Hard
40 Sliding Window https://leetcode.com/problems/replace-the-substring-for-balanced-string Medium
41 Sliding Window https://leetcode.com/problems/swap-for-longest-repeated-character-substring Medium
42 Sliding Window https://leetcode.com/problems/maximum-number-of-vowels-in-a-substring-of-given-length
Medium
43 Sliding Window https://leetcode.com/problems/fruit-into-baskets Medium
44 Sliding Window https://leetcode.com/problems/get-equal-substrings-within-budget Medium
45 Sliding Window https://leetcode.com/problems/maximum-number-of-occurrences-of-a-substring Medium
46 Sliding Window https://leetcode.com/problems/number-of-sub-arrays-of-size-k-and-average-greater-than-or-equal-to-threshold
Medium
47 Sliding Window https://leetcode.com/problems/longest-nice-substring Easy
48 Sliding Window https://leetcode.com/problems/substrings-of-size-three-with-distinct-characters Easy
49 Sliding Window https://leetcode.com/problems/minimum-adjacent-swaps-for-k-consecutive-onesHard
50 Sliding Window https://leetcode.com/problems/longest-substring-of-all-vowels-in-order Medium
51 Sliding Window https://leetcode.com/problems/maximum-number-of-visible-points Hard
52 Sliding Window https://leetcode.com/problems/maximize-the-confusion-of-an-exam Medium
53 Sliding Window https://leetcode.com/problems/maximum-fruits-harvested-after-at-most-k-steps Hard
54 Sliding Window https://leetcode.com/problems/k-radius-subarray-averages Medium
55 Sliding Window https://leetcode.com/problems/distinct-echo-substrings Hard
 Crack The Coding Interview - Dinesh Varyani
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# Topic Question Difficulty

1 Linked List https://leetcode.com/problems/add-two-numbers Medium

2 Linked List https://leetcode.com/problems/lru-cache Medium
3 Linked List https://leetcode.com/problems/reverse-linked-list Easy
4 Linked List https://leetcode.com/problems/merge-k-sorted-lists Hard
5 Linked List https://leetcode.com/problems/merge-two-sorted-lists Easy
6 Linked List https://leetcode.com/problems/remove-nth-node-from-end-of-list Medium
7 Linked List https://leetcode.com/problems/intersection-of-two-linked-lists Easy
8 Linked List https://leetcode.com/problems/palindrome-linked-list Easy
9 Linked List https://leetcode.com/problems/copy-list-with-random-pointer Medium
10 Linked List https://leetcode.com/problems/linked-list-cycle Easy
11 Linked List https://leetcode.com/problems/flatten-binary-tree-to-linked-list Medium
12 Linked List https://leetcode.com/problems/reverse-nodes-in-k-group Hard
13 Linked List https://leetcode.com/problems/linked-list-cycle-ii Medium
14 Linked List https://leetcode.com/problems/sort-list Medium
15 Linked List https://leetcode.com/problems/swap-nodes-in-pairs Medium
16 Linked List https://leetcode.com/problems/reverse-linked-list-ii Medium
17 Linked List https://leetcode.com/problems/reorder-list Medium
18 Linked List https://leetcode.com/problems/odd-even-linked-list Medium
19 Linked List https://leetcode.com/problems/middle-of-the-linked-list Easy
20 Linked List https://leetcode.com/problems/remove-linked-list-elements Easy
21 Linked List https://leetcode.com/problems/remove-duplicates-from-sorted-list-ii Medium
22 Linked List https://leetcode.com/problems/convert-sorted-list-to-binary-search-tree Medium
23 Linked List https://leetcode.com/problems/remove-duplicates-from-sorted-list Easy
24 Linked List https://leetcode.com/problems/delete-node-in-a-linked-list Easy
25 Linked List https://leetcode.com/problems/rotate-list Medium
26 Linked List https://leetcode.com/problems/flatten-a-multilevel-doubly-linked-list Medium
27 Linked List https://leetcode.com/problems/add-two-numbers-ii Medium
28 Linked List https://leetcode.com/problems/partition-list Medium
29 Linked List https://leetcode.com/problems/lfu-cache Hard
30 Linked List https://leetcode.com/problems/design-hashmap Easy
31 Linked List https://leetcode.com/problems/convert-binary-number-in-a-linked-list-to-integer Easy
32 Linked List https://leetcode.com/problems/next-greater-node-in-linked-list Medium
33 Linked List https://leetcode.com/problems/insertion-sort-list Medium
34 Linked List https://leetcode.com/problems/design-twitter Medium
35 Linked List https://leetcode.com/problems/split-linked-list-in-parts Medium
36 Linked List https://leetcode.com/problems/design-circular-queue Medium
37 Linked List https://leetcode.com/problems/swapping-nodes-in-a-linked-list Medium
38 Linked List https://leetcode.com/problems/remove-zero-sum-consecutive-nodes-from-linked-listMedium
39 Linked List https://leetcode.com/problems/design-linked-list Medium
40 Linked List https://leetcode.com/problems/linked-list-in-binary-tree Medium
41 Linked List https://leetcode.com/problems/linked-list-random-node Medium
42 Linked List https://leetcode.com/problems/design-hashset Easy
43 Linked List https://leetcode.com/problems/all-oone-data-structure Hard
44 Linked List https://leetcode.com/problems/design-browser-history Medium
45 Linked List https://leetcode.com/problems/merge-in-between-linked-lists Medium
46 Linked List https://leetcode.com/problems/linked-list-components Medium
47 Linked List https://leetcode.com/problems/design-circular-deque Medium
48 Linked List https://leetcode.com/problems/design-front-middle-back-queue Medium
49 Linked List https://leetcode.com/problems/design-skiplist Hard
50 Linked List https://leetcode.com/problems/delete-the-middle-node-of-a-linked-list Medium
51 Linked List https://leetcode.com/problems/find-the-minimum-and-maximum-number-of-nodes-between-critical-points
Medium
52 Linked List https://leetcode.com/problems/reverse-nodes-in-even-length-groups Medium
 Crack The Coding Interview - Dinesh Varyani
https://www.youtube.com/user/hubberspot?sub_confirmation=1

# Topic Question Difficulty

1 Union Find https://leetcode.com/problems/number-of-islands Medium

2 Union Find https://leetcode.com/problems/longest-consecutive-sequence Medium
3 Union Find https://leetcode.com/problems/max-area-of-island Medium
4 Union Find https://leetcode.com/problems/evaluate-division Medium
5 Union Find https://leetcode.com/problems/number-of-provinces Medium
6 Union Find https://leetcode.com/problems/surrounded-regions Medium
7 Union Find https://leetcode.com/problems/accounts-merge Medium
8 Union Find https://leetcode.com/problems/is-graph-bipartite Medium
9 Union Find https://leetcode.com/problems/redundant-connection Medium
10 Union Find https://leetcode.com/problems/most-stones-removed-with-same-row-or-column Medium
11 Union Find https://leetcode.com/problems/possible-bipartition Medium
12 Union Find https://leetcode.com/problems/making-a-large-island Hard
13 Union Find https://leetcode.com/problems/regions-cut-by-slashes Medium
14 Union Find https://leetcode.com/problems/path-with-minimum-effort Medium
15 Union Find https://leetcode.com/problems/swim-in-rising-water Hard
16 Union Find https://leetcode.com/problems/number-of-operations-to-make-network-connected Medium
17 Union Find https://leetcode.com/problems/couples-holding-hands Hard
18 Union Find https://leetcode.com/problems/redundant-connection-ii Hard
19 Union Find https://leetcode.com/problems/number-of-closed-islands Medium
20 Union Find https://leetcode.com/problems/satisfiability-of-equality-equations Medium
21 Union Find https://leetcode.com/problems/smallest-string-with-swaps Medium
22 Union Find https://leetcode.com/problems/largest-component-size-by-common-factor Hard
23 Union Find https://leetcode.com/problems/min-cost-to-connect-all-points Medium
24 Union Find https://leetcode.com/problems/number-of-enclaves Medium
25 Union Find https://leetcode.com/problems/count-servers-that-communicate Medium
26 Union Find https://leetcode.com/problems/bricks-falling-when-hit Hard
27 Union Find https://leetcode.com/problems/similar-string-groups Hard
28 Union Find https://leetcode.com/problems/validate-binary-tree-nodes Medium
29 Union Find https://leetcode.com/problems/count-sub-islands Medium
30 Union Find https://leetcode.com/problems/minimize-malware-spread Hard
31 Union Find https://leetcode.com/problems/rank-transform-of-a-matrix Hard
32 Union Find https://leetcode.com/problems/remove-max-number-of-edges-to-keep-graph-fully-traversable
Hard
33 Union Find https://leetcode.com/problems/minimize-hamming-distance-after-swap-operations Medium
34 Union Find https://leetcode.com/problems/check-if-there-is-a-valid-path-in-a-grid Medium
35 Union Find https://leetcode.com/problems/detect-cycles-in-2d-grid Medium
36 Union Find https://leetcode.com/problems/checking-existence-of-edge-length-limited-paths Hard
37 Union Find https://leetcode.com/problems/find-critical-and-pseudo-critical-edges-in-minimum-spanning-tree
Hard
38 Union Find https://leetcode.com/problems/minimize-malware-spread-ii Hard
39 Union Find https://leetcode.com/problems/last-day-where-you-can-still-cross Hard
40 Union Find https://leetcode.com/problems/number-of-ways-to-reorder-array-to-get-same-bstHard
41 Union Find https://leetcode.com/problems/find-all-people-with-secret Hard
42 Union Find https://leetcode.com/problems/graph-connectivity-with-threshold Hard
43 Union Find https://leetcode.com/problems/process-restricted-friend-requests Hard
44 Union Find https://leetcode.com/problems/smallest-missing-genetic-value-in-each-subtree Hard
45 Union Find https://leetcode.com/problems/gcd-sort-of-an-array Hard
 Crack The Coding Interview - Dinesh Varyani
https://www.youtube.com/user/hubberspot?sub_confirmation=1

# Topic Question Difficulty

1 Monotonic Stack https://leetcode.com/problems/trapping-rain-water Hard

2 Monotonic Stack https://leetcode.com/problems/largest-rectangle-in-histogram Hard
3 Monotonic Stack https://leetcode.com/problems/daily-temperatures Medium
4 Monotonic Stack https://leetcode.com/problems/maximal-rectangle Hard
5 Monotonic Stack https://leetcode.com/problems/shortest-unsorted-continuous-subarray Medium
6 Monotonic Stack https://leetcode.com/problems/remove-k-digits Medium
7 Monotonic Stack https://leetcode.com/problems/next-greater-element-ii Medium
8 Monotonic Stack https://leetcode.com/problems/remove-duplicate-letters Medium
9 Monotonic Stack https://leetcode.com/problems/maximum-binary-tree Medium
10 Monotonic Stack https://leetcode.com/problems/construct-binary-search-tree-from-preorder-traversal
Medium
11 Monotonic Stack https://leetcode.com/problems/132-pattern Medium
12 Monotonic Stack https://leetcode.com/problems/sum-of-subarray-minimums Medium
13 Monotonic Stack https://leetcode.com/problems/minimum-cost-tree-from-leaf-values Medium
14 Monotonic Stack https://leetcode.com/problems/online-stock-span Medium
15 Monotonic Stack https://leetcode.com/problems/next-greater-node-in-linked-list Medium
16 Monotonic Stack https://leetcode.com/problems/next-greater-element-i Easy
17 Monotonic Stack https://leetcode.com/problems/max-chunks-to-make-sorted Medium
18 Monotonic Stack https://leetcode.com/problems/count-submatrices-with-all-ones Medium
19 Monotonic Stack https://leetcode.com/problems/smallest-subsequence-of-distinct-characters Medium
20 Monotonic Stack https://leetcode.com/problems/odd-even-jump Hard
21 Monotonic Stack https://leetcode.com/problems/create-maximum-number Hard
22 Monotonic Stack https://leetcode.com/problems/car-fleet Medium
23 Monotonic Stack https://leetcode.com/problems/find-the-most-competitive-subsequence Medium
24 Monotonic Stack https://leetcode.com/problems/maximum-width-ramp Medium
25 Monotonic Stack https://leetcode.com/problems/max-chunks-to-make-sorted-ii Hard
26 Monotonic Stack https://leetcode.com/problems/longest-well-performing-interval Medium
27 Monotonic Stack https://leetcode.com/problems/shortest-subarray-to-be-removed-to-make-array-sorted
Medium
28 Monotonic Stack https://leetcode.com/problems/final-prices-with-a-special-discount-in-a-shop Easy
29 Monotonic Stack https://leetcode.com/problems/minimum-number-of-increments-on-subarrays-to-form-a-target-array
Hard
30 Monotonic Stack https://leetcode.com/problems/maximum-subarray-min-product Medium
31 Monotonic Stack https://leetcode.com/problems/number-of-visible-people-in-a-queue Hard
32 Monotonic Stack https://leetcode.com/problems/car-fleet-ii Hard
33 Monotonic Stack https://leetcode.com/problems/maximum-score-of-a-good-subarray Hard
34 Monotonic Stack https://leetcode.com/problems/the-number-of-weak-characters-in-the-game Medium
35 Monotonic Stack https://leetcode.com/problems/sum-of-subarray-ranges Medium
36 Monotonic Stack https://leetcode.com/problems/smallest-k-length-subsequence-with-occurrences-of-a-letter
Hard
 Crack The Coding Interview - Dinesh Varyani
https://www.youtube.com/user/hubberspot?sub_confirmation=1

# Topic Question Difficulty

1 Divide and Conquer https://leetcode.com/problems/maximum-subarray Easy

2 Divide and Conquer https://leetcode.com/problems/median-of-two-sorted-arrays Hard
3 Divide and Conquer https://leetcode.com/problems/merge-k-sorted-lists Hard
4 Divide and Conquer https://leetcode.com/problems/kth-largest-element-in-an-array Medium
5 Divide and Conquer https://leetcode.com/problems/majority-element Easy
6 Divide and Conquer https://leetcode.com/problems/construct-binary-tree-from-preorder-and-inorder-traversal
Medium
7 Divide and Conquer https://leetcode.com/problems/top-k-frequent-elements Medium
8 Divide and Conquer https://leetcode.com/problems/search-a-2d-matrix-ii Medium
9 Divide and Conquer https://leetcode.com/problems/sort-list Medium
10 Divide and Conquer https://leetcode.com/problems/convert-sorted-array-to-binary-search-tree Easy
11 Divide and Conquer https://leetcode.com/problems/count-of-smaller-numbers-after-self Hard
12 Divide and Conquer https://leetcode.com/problems/k-closest-points-to-origin Medium
13 Divide and Conquer https://leetcode.com/problems/convert-sorted-list-to-binary-search-tree Medium
14 Divide and Conquer https://leetcode.com/problems/construct-binary-tree-from-inorder-and-postorder-traversal
Medium
15 Divide and Conquer https://leetcode.com/problems/the-skyline-problem Hard
16 Divide and Conquer https://leetcode.com/problems/longest-substring-with-at-least-k-repeating-characters
Medium
17 Divide and Conquer https://leetcode.com/problems/maximum-binary-tree Medium
18 Divide and Conquer https://leetcode.com/problems/maximum-sum-circular-subarray Medium
19 Divide and Conquer https://leetcode.com/problems/reverse-bits Easy
20 Divide and Conquer https://leetcode.com/problems/reverse-pairs Hard
21 Divide and Conquer https://leetcode.com/problems/wiggle-sort-ii Medium
22 Divide and Conquer https://leetcode.com/problems/construct-binary-tree-from-preorder-and-postorder-traversal
Medium
23 Divide and Conquer https://leetcode.com/problems/sort-an-array Medium
24 Divide and Conquer https://leetcode.com/problems/balance-a-binary-search-tree Medium
25 Divide and Conquer https://leetcode.com/problems/count-of-range-sum Hard
26 Divide and Conquer https://leetcode.com/problems/beautiful-array Medium
27 Divide and Conquer https://leetcode.com/problems/find-a-peak-element-ii Medium
28 Divide and Conquer https://leetcode.com/problems/create-sorted-array-through-instructions Hard
29 Divide and Conquer https://leetcode.com/problems/construct-quad-tree Medium
30 Divide and Conquer https://leetcode.com/problems/super-pow Medium
31 Divide and Conquer https://leetcode.com/problems/number-of-ways-to-reorder-array-to-get-same-bstHard
32 Divide and Conquer https://leetcode.com/problems/find-the-kth-largest-integer-in-the-array Medium
33 Divide and Conquer https://leetcode.com/problems/find-kth-largest-xor-coordinate-value Medium
34 Divide and Conquer https://leetcode.com/problems/find-array-given-subset-sums Hard
35 Divide and Conquer https://leetcode.com/problems/logical-or-of-two-binary-grids-represented-as-quad-trees
Medium
 Crack The Coding Interview - Dinesh Varyani
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# Topic Question Difficulty

1 Recursion https://leetcode.com/problems/add-two-numbers Medium

2 Recursion https://leetcode.com/problems/reverse-linked-list Easy
3 Recursion https://leetcode.com/problems/merge-two-sorted-lists Easy
4 Recursion https://leetcode.com/problems/palindrome-linked-list Easy
5 Recursion https://leetcode.com/problems/regular-expression-matching Hard
6 Recursion https://leetcode.com/problems/decode-string Medium
7 Recursion https://leetcode.com/problems/reverse-nodes-in-k-group Hard
8 Recursion https://leetcode.com/problems/swap-nodes-in-pairs Medium
9 Recursion https://leetcode.com/problems/reorder-list Medium
10 Recursion https://leetcode.com/problems/remove-linked-list-elements Easy
11 Recursion https://leetcode.com/problems/wildcard-matching Hard
12 Recursion https://leetcode.com/problems/powx-n Medium
13 Recursion https://leetcode.com/problems/reverse-string Easy
14 Recursion https://leetcode.com/problems/basic-calculator Hard
15 Recursion https://leetcode.com/problems/permutation-sequence Hard
16 Recursion https://leetcode.com/problems/different-ways-to-add-parentheses Medium
17 Recursion https://leetcode.com/problems/power-of-two Easy
18 Recursion https://leetcode.com/problems/predict-the-winner Medium
19 Recursion https://leetcode.com/problems/fibonacci-number Easy
20 Recursion https://leetcode.com/problems/all-possible-full-binary-trees Medium
21 Recursion https://leetcode.com/problems/integer-to-english-words Hard
22 Recursion https://leetcode.com/problems/k-th-symbol-in-grammar Medium
23 Recursion https://leetcode.com/problems/power-of-four Easy
24 Recursion https://leetcode.com/problems/find-the-winner-of-the-circular-game Medium
25 Recursion https://leetcode.com/problems/power-of-three Easy
26 Recursion https://leetcode.com/problems/number-of-digit-one Hard
27 Recursion https://leetcode.com/problems/parsing-a-boolean-expression Hard
28 Recursion https://leetcode.com/problems/special-binary-string Hard
29 Recursion https://leetcode.com/problems/find-kth-bit-in-nth-binary-string Medium
30 Recursion https://leetcode.com/problems/parse-lisp-expression Hard
31 Recursion https://leetcode.com/problems/count-good-numbers Medium
32 Recursion https://leetcode.com/problems/maximize-number-of-nice-divisors Hard
33 Recursion https://leetcode.com/problems/basic-calculator-iv Hard
34 Recursion https://leetcode.com/problems/minimum-non-zero-product-of-the-array-elementsMedium
 Crack The Coding Interview - Dinesh Varyani
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# Topic Question Difficulty

1 Ordered Set https://leetcode.com/problems/count-of-smaller-numbers-after-self Hard

2 Ordered Set https://leetcode.com/problems/the-skyline-problem Hard
3 Ordered Set https://leetcode.com/problems/132-pattern Medium
4 Ordered Set https://leetcode.com/problems/maximum-frequency-stack Hard
5 Ordered Set https://leetcode.com/problems/reverse-pairs Hard
6 Ordered Set https://leetcode.com/problems/contains-duplicate-iii Medium
7 Ordered Set https://leetcode.com/problems/longest-continuous-subarray-with-absolute-diff-less-than-or-equal-to-limit
Medium
8 Ordered Set https://leetcode.com/problems/max-sum-of-rectangle-no-larger-than-k Hard
9 Ordered Set https://leetcode.com/problems/my-calendar-i Medium
10 Ordered Set https://leetcode.com/problems/count-of-range-sum Hard
11 Ordered Set https://leetcode.com/problems/odd-even-jump Hard
12 Ordered Set https://leetcode.com/problems/my-calendar-ii Medium
13 Ordered Set https://leetcode.com/problems/exam-room Medium
14 Ordered Set https://leetcode.com/problems/range-module Hard
15 Ordered Set https://leetcode.com/problems/rectangle-area-ii Hard
16 Ordered Set https://leetcode.com/problems/my-calendar-iii Hard
17 Ordered Set https://leetcode.com/problems/data-stream-as-disjoint-intervals Hard
18 Ordered Set https://leetcode.com/problems/minimize-deviation-in-array Hard
19 Ordered Set https://leetcode.com/problems/create-sorted-array-through-instructions Hard
20 Ordered Set https://leetcode.com/problems/falling-squares Hard
21 Ordered Set https://leetcode.com/problems/minimum-absolute-sum-difference Medium
22 Ordered Set https://leetcode.com/problems/random-point-in-non-overlapping-rectangles Medium
23 Ordered Set https://leetcode.com/problems/the-number-of-the-smallest-unoccupied-chair Medium
24 Ordered Set https://leetcode.com/problems/partition-array-into-two-arrays-to-minimize-sum-difference
Hard
25 Ordered Set https://leetcode.com/problems/find-servers-that-handled-most-number-of-requestsHard
26 Ordered Set https://leetcode.com/problems/stock-price-fluctuation Medium
27 Ordered Set https://leetcode.com/problems/finding-mk-average Hard
28 Ordered Set https://leetcode.com/problems/display-table-of-food-orders-in-a-restaurant Medium
29 Ordered Set https://leetcode.com/problems/design-movie-rental-system Hard
30 Ordered Set https://leetcode.com/problems/tweet-counts-per-frequency Medium
31 Ordered Set https://leetcode.com/problems/sequentially-ordinal-rank-tracker Hard
 Crack The Coding Interview - Dinesh Varyani
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# Topic Question Difficulty

1 Bitmask https://leetcode.com/problems/partition-to-k-equal-sum-subsets Medium

2 Bitmask https://leetcode.com/problems/beautiful-arrangement Medium
3 Bitmask https://leetcode.com/problems/can-i-win Medium
4 Bitmask https://leetcode.com/problems/matchsticks-to-square Medium
5 Bitmask https://leetcode.com/problems/shortest-path-visiting-all-nodes Hard
6 Bitmask https://leetcode.com/problems/find-the-shortest-superstring Hard
7 Bitmask https://leetcode.com/problems/shopping-offers Medium
8 Bitmask https://leetcode.com/problems/split-array-with-same-average Hard
9 Bitmask https://leetcode.com/problems/stickers-to-spell-word Hard
10 Bitmask https://leetcode.com/problems/smallest-sufficient-team Hard
11 Bitmask https://leetcode.com/problems/number-of-squareful-arrays Hard
12 Bitmask https://leetcode.com/problems/maximum-score-words-formed-by-letters Hard
13 Bitmask https://leetcode.com/problems/number-of-ways-to-wear-different-hats-to-each-other
Hard
14 Bitmask https://leetcode.com/problems/parallel-courses-ii Hard
15 Bitmask https://leetcode.com/problems/maximum-students-taking-exam Hard
16 Bitmask https://leetcode.com/problems/find-minimum-time-to-finish-all-jobs Hard
17 Bitmask https://leetcode.com/problems/minimum-number-of-work-sessions-to-finish-the-tasks
Medium
18 Bitmask https://leetcode.com/problems/closest-subsequence-sum Hard
19 Bitmask https://leetcode.com/problems/maximum-compatibility-score-sum Medium
20 Bitmask https://leetcode.com/problems/minimum-xor-sum-of-two-arrays Hard
21 Bitmask https://leetcode.com/problems/maximum-product-of-the-length-of-two-palindromic-subsequences
Medium
22 Bitmask https://leetcode.com/problems/maximize-score-after-n-operations Hard
23 Bitmask https://leetcode.com/problems/minimum-cost-to-connect-two-groups-of-points Hard
24 Bitmask https://leetcode.com/problems/partition-array-into-two-arrays-to-minimize-sum-difference
Hard
25 Bitmask https://leetcode.com/problems/count-subtrees-with-max-distance-between-citiesHard
26 Bitmask https://leetcode.com/problems/maximum-number-of-groups-getting-fresh-donutsHard
27 Bitmask https://leetcode.com/problems/maximize-grid-happiness Hard
28 Bitmask https://leetcode.com/problems/distribute-repeating-integers Hard
29 Bitmask https://leetcode.com/problems/the-number-of-good-subsets Hard
30 Bitmask https://leetcode.com/problems/minimum-incompatibility Hard
 Crack The Coding Interview - Dinesh Varyani
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# Topic Question Difficulty

1 Trie https://leetcode.com/problems/word-break Medium

2 Trie https://leetcode.com/problems/implement-trie-prefix-tree Medium
3 Trie https://leetcode.com/problems/word-search-ii Hard
4 Trie https://leetcode.com/problems/word-break-ii Hard
5 Trie https://leetcode.com/problems/top-k-frequent-words Medium
6 Trie https://leetcode.com/problems/design-add-and-search-words-data-structure Medium
7 Trie https://leetcode.com/problems/maximum-xor-of-two-numbers-in-an-array Medium
8 Trie https://leetcode.com/problems/number-of-matching-subsequences Medium
9 Trie https://leetcode.com/problems/palindrome-pairs Hard
10 Trie https://leetcode.com/problems/search-suggestions-system Medium
11 Trie https://leetcode.com/problems/concatenated-words Hard
12 Trie https://leetcode.com/problems/stream-of-characters Hard
13 Trie https://leetcode.com/problems/replace-words Medium
14 Trie https://leetcode.com/problems/longest-word-in-dictionary Medium
15 Trie https://leetcode.com/problems/map-sum-pairs Medium
16 Trie https://leetcode.com/problems/lexicographical-numbers Medium
17 Trie https://leetcode.com/problems/number-of-valid-words-for-each-puzzle Hard
18 Trie https://leetcode.com/problems/prefix-and-suffix-search Hard
19 Trie https://leetcode.com/problems/implement-magic-dictionary Medium
20 Trie https://leetcode.com/problems/short-encoding-of-words Medium
21 Trie https://leetcode.com/problems/remove-sub-folders-from-the-filesystem Medium
22 Trie https://leetcode.com/problems/k-th-smallest-in-lexicographical-order Hard
23 Trie https://leetcode.com/problems/camelcase-matching Medium
24 Trie https://leetcode.com/problems/maximum-xor-with-an-element-from-array Hard
25 Trie https://leetcode.com/problems/count-pairs-with-xor-in-a-range Hard
26 Trie https://leetcode.com/problems/maximum-genetic-difference-query Hard
27 Trie https://leetcode.com/problems/distinct-echo-substrings Hard
28 Trie https://leetcode.com/problems/delete-duplicate-folders-in-system Hard
 Crack The Coding Interview - Dinesh Varyani
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# Topic Question Difficulty

1 Binary Search Tree https://leetcode.com/problems/validate-binary-search-tree Medium

2 Binary Search Tree https://leetcode.com/problems/unique-binary-search-trees Medium
3 Binary Search Tree https://leetcode.com/problems/convert-sorted-array-to-binary-search-tree Easy
4 Binary Search Tree https://leetcode.com/problems/kth-smallest-element-in-a-bst Medium
5 Binary Search Tree https://leetcode.com/problems/lowest-common-ancestor-of-a-binary-search-tree Easy
6 Binary Search Tree https://leetcode.com/problems/binary-search-tree-iterator Medium
7 Binary Search Tree https://leetcode.com/problems/delete-node-in-a-bst Medium
8 Binary Search Tree https://leetcode.com/problems/unique-binary-search-trees-ii Medium
9 Binary Search Tree https://leetcode.com/problems/convert-sorted-list-to-binary-search-tree Medium
10 Binary Search Tree https://leetcode.com/problems/recover-binary-search-tree Medium
11 Binary Search Tree https://leetcode.com/problems/range-sum-of-bst Easy
12 Binary Search Tree https://leetcode.com/problems/trim-a-binary-search-tree Medium
13 Binary Search Tree https://leetcode.com/problems/construct-binary-search-tree-from-preorder-traversal
Medium
14 Binary Search Tree https://leetcode.com/problems/two-sum-iv-input-is-a-bst Easy
15 Binary Search Tree https://leetcode.com/problems/convert-bst-to-greater-tree Medium
16 Binary Search Tree https://leetcode.com/problems/serialize-and-deserialize-bst Medium
17 Binary Search Tree https://leetcode.com/problems/insert-into-a-binary-search-tree Medium
18 Binary Search Tree https://leetcode.com/problems/search-in-a-binary-search-tree Easy
19 Binary Search Tree https://leetcode.com/problems/binary-search-tree-to-greater-sum-tree Medium
20 Binary Search Tree https://leetcode.com/problems/increasing-order-search-tree Easy
21 Binary Search Tree https://leetcode.com/problems/find-mode-in-binary-search-tree Easy
22 Binary Search Tree https://leetcode.com/problems/kth-largest-element-in-a-stream Easy
23 Binary Search Tree https://leetcode.com/problems/minimum-absolute-difference-in-bst Easy
24 Binary Search Tree https://leetcode.com/problems/balance-a-binary-search-tree Medium
25 Binary Search Tree https://leetcode.com/problems/minimum-distance-between-bst-nodes Easy
26 Binary Search Tree https://leetcode.com/problems/all-elements-in-two-binary-search-trees Medium
27 Binary Search Tree https://leetcode.com/problems/maximum-sum-bst-in-binary-tree Hard
28 Binary Search Tree https://leetcode.com/problems/number-of-ways-to-reorder-array-to-get-same-bstHard
 Crack The Coding Interview - Dinesh Varyani
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# Topic Question Difficulty

1 Memoization https://leetcode.com/problems/climbing-stairs Easy

2 Memoization https://leetcode.com/problems/word-break Medium
3 Memoization https://leetcode.com/problems/longest-increasing-path-in-a-matrix Hard
4 Memoization https://leetcode.com/problems/partition-to-k-equal-sum-subsets Medium
5 Memoization https://leetcode.com/problems/word-break-ii Hard
6 Memoization https://leetcode.com/problems/different-ways-to-add-parentheses Medium
7 Memoization https://leetcode.com/problems/fibonacci-number Easy
8 Memoization https://leetcode.com/problems/all-possible-full-binary-trees Medium
9 Memoization https://leetcode.com/problems/can-i-win Medium
10 Memoization https://leetcode.com/problems/remove-boxes Hard
11 Memoization https://leetcode.com/problems/n-th-tribonacci-number Easy
12 Memoization https://leetcode.com/problems/shopping-offers Medium
13 Memoization https://leetcode.com/problems/sort-integers-by-the-power-value Medium
14 Memoization https://leetcode.com/problems/integer-replacement Medium
15 Memoization https://leetcode.com/problems/minimum-number-of-days-to-eat-n-oranges Hard
16 Memoization https://leetcode.com/problems/cat-and-mouse Hard
17 Memoization https://leetcode.com/problems/number-of-ways-of-cutting-a-pizza Hard
18 Memoization https://leetcode.com/problems/largest-color-value-in-a-directed-graph Hard
19 Memoization https://leetcode.com/problems/number-of-ways-to-reorder-array-to-get-same-bstHard
20 Memoization https://leetcode.com/problems/zuma-game Hard
21 Memoization https://leetcode.com/problems/count-all-possible-routes Hard
22 Memoization https://leetcode.com/problems/minimum-one-bit-operations-to-make-integers-zeroHard
23 Memoization https://leetcode.com/problems/maximum-number-of-groups-getting-fresh-donutsHard
24 Memoization https://leetcode.com/problems/maximize-grid-happiness Hard
25 Memoization https://leetcode.com/problems/the-earliest-and-latest-rounds-where-players-compete
Hard
26 Memoization https://leetcode.com/problems/cat-and-mouse-ii Hard
27 Memoization https://leetcode.com/problems/the-score-of-students-solving-math-expression Hard
 Crack The Coding Interview - Dinesh Varyani
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# Topic Question Difficulty

1 Queue https://leetcode.com/problems/sliding-window-maximum Hard

2 Queue https://leetcode.com/problems/first-unique-character-in-a-string Easy
3 Queue https://leetcode.com/problems/flatten-nested-list-iterator Medium
4 Queue https://leetcode.com/problems/implement-queue-using-stacks Easy
5 Queue https://leetcode.com/problems/maximum-sum-circular-subarray Medium
6 Queue https://leetcode.com/problems/shortest-subarray-with-sum-at-least-k Hard
7 Queue https://leetcode.com/problems/longest-continuous-subarray-with-absolute-diff-less-than-or-equal-to-limit
Medium
8 Queue https://leetcode.com/problems/implement-stack-using-queues Easy
9 Queue https://leetcode.com/problems/reveal-cards-in-increasing-order Medium
10 Queue https://leetcode.com/problems/design-circular-queue Medium
11 Queue https://leetcode.com/problems/jump-game-vi Medium
12 Queue https://leetcode.com/problems/product-of-the-last-k-numbers Medium
13 Queue https://leetcode.com/problems/find-the-winner-of-the-circular-game Medium
14 Queue https://leetcode.com/problems/max-value-of-equation Hard
15 Queue https://leetcode.com/problems/number-of-recent-calls Easy
16 Queue https://leetcode.com/problems/constrained-subsequence-sum Hard
17 Queue https://leetcode.com/problems/number-of-students-unable-to-eat-lunch Easy
18 Queue https://leetcode.com/problems/design-circular-deque Medium
19 Queue https://leetcode.com/problems/stamping-the-sequence Hard
20 Queue https://leetcode.com/problems/dota2-senate Medium
21 Queue https://leetcode.com/problems/design-front-middle-back-queue Medium
22 Queue https://leetcode.com/problems/delivering-boxes-from-storage-to-ports Hard
23 Queue https://leetcode.com/problems/time-needed-to-buy-tickets Easy
24 Queue https://leetcode.com/problems/finding-mk-average Hard
25 Queue https://leetcode.com/problems/maximum-number-of-tasks-you-can-assign Hard
 Crack The Coding Interview - Dinesh Varyani
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# Topic Question Difficulty

1 Geometry https://leetcode.com/problems/k-closest-points-to-origin Medium

2 Geometry https://leetcode.com/problems/minimum-area-rectangle Medium
3 Geometry https://leetcode.com/problems/rectangle-overlap Easy
4 Geometry https://leetcode.com/problems/minimum-time-visiting-all-points Easy
5 Geometry https://leetcode.com/problems/max-points-on-a-line Hard
6 Geometry https://leetcode.com/problems/check-if-it-is-a-straight-line Easy
7 Geometry https://leetcode.com/problems/rectangle-area Medium
8 Geometry https://leetcode.com/problems/valid-square Medium
9 Geometry https://leetcode.com/problems/erect-the-fence Hard
10 Geometry https://leetcode.com/problems/matrix-cells-in-distance-order Easy
11 Geometry https://leetcode.com/problems/queries-on-number-of-points-inside-a-circle Medium
12 Geometry https://leetcode.com/problems/surface-area-of-3d-shapes Easy
13 Geometry https://leetcode.com/problems/projection-area-of-3d-shapes Easy
14 Geometry https://leetcode.com/problems/mirror-reflection Medium
15 Geometry https://leetcode.com/problems/generate-random-point-in-a-circle Medium
16 Geometry https://leetcode.com/problems/maximum-number-of-visible-points Hard
17 Geometry https://leetcode.com/problems/largest-triangle-area Easy
18 Geometry https://leetcode.com/problems/minimum-area-rectangle-ii Medium
19 Geometry https://leetcode.com/problems/self-crossing Hard
20 Geometry https://leetcode.com/problems/circle-and-rectangle-overlapping Medium
21 Geometry https://leetcode.com/problems/valid-boomerang Easy
22 Geometry https://leetcode.com/problems/detonate-the-maximum-bombs Medium
23 Geometry https://leetcode.com/problems/best-position-for-a-service-centre Hard
24 Geometry https://leetcode.com/problems/maximum-number-of-darts-inside-of-a-circular-dartboard
Hard
 Crack The Coding Interview - Dinesh Varyani
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# Topic Question Difficulty

1 Enumeration https://leetcode.com/problems/count-primes Medium

2 Enumeration https://leetcode.com/problems/longest-mountain-in-array Medium
3 Enumeration https://leetcode.com/problems/consecutive-numbers-sum Hard
4 Enumeration https://leetcode.com/problems/sequential-digits Medium
5 Enumeration https://leetcode.com/problems/reordered-power-of-2 Medium
6 Enumeration https://leetcode.com/problems/largest-time-for-given-digits Medium
7 Enumeration https://leetcode.com/problems/detect-pattern-of-length-m-repeated-k-or-more-times
Easy
8 Enumeration https://leetcode.com/problems/count-good-triplets Easy
9 Enumeration https://leetcode.com/problems/super-palindromes Hard
10 Enumeration https://leetcode.com/problems/count-subtrees-with-max-distance-between-citiesHard
11 Enumeration https://leetcode.com/problems/maximum-number-of-ways-to-partition-an-array Hard
12 Enumeration https://leetcode.com/problems/maximum-number-of-achievable-transfer-requestsHard
13 Enumeration https://leetcode.com/problems/count-special-quadruplets Easy
14 Enumeration https://leetcode.com/problems/recover-the-original-array Hard
15 Enumeration https://leetcode.com/problems/longest-subsequence-repeated-k-times Hard
16 Enumeration https://leetcode.com/problems/count-square-sum-triples Easy
17 Enumeration https://leetcode.com/problems/finding-3-digit-even-numbers Easy
18 Enumeration https://leetcode.com/problems/check-if-word-can-be-placed-in-crossword Medium
19 Enumeration https://leetcode.com/problems/next-greater-numerically-balanced-number Medium
20 Enumeration https://leetcode.com/problems/check-if-move-is-legal Medium
21 Enumeration https://leetcode.com/problems/sum-of-k-mirror-numbers Hard
22 Enumeration https://leetcode.com/problems/coordinate-with-maximum-network-quality Medium
 Crack The Coding Interview - Dinesh Varyani
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# Topic Question Difficulty

1 Game Theory https://leetcode.com/problems/predict-the-winner Medium

2 Game Theory https://leetcode.com/problems/stone-game Medium
3 Game Theory https://leetcode.com/problems/can-i-win Medium
4 Game Theory https://leetcode.com/problems/guess-number-higher-or-lower-ii Medium
5 Game Theory https://leetcode.com/problems/stone-game-ii Medium
6 Game Theory https://leetcode.com/problems/divisor-game Easy
7 Game Theory https://leetcode.com/problems/guess-the-word Hard
8 Game Theory https://leetcode.com/problems/nim-game Easy
9 Game Theory https://leetcode.com/problems/stone-game-iii Hard
10 Game Theory https://leetcode.com/problems/stone-game-vii Medium
11 Game Theory https://leetcode.com/problems/cat-and-mouse Hard
12 Game Theory https://leetcode.com/problems/stone-game-iv Hard
13 Game Theory https://leetcode.com/problems/maximum-number-of-coins-you-can-get Medium
14 Game Theory https://leetcode.com/problems/stone-game-vi Medium
15 Game Theory https://leetcode.com/problems/stone-game-v Hard
16 Game Theory https://leetcode.com/problems/sum-game Medium
17 Game Theory https://leetcode.com/problems/stone-game-viii Hard
18 Game Theory https://leetcode.com/problems/remove-colored-pieces-if-both-neighbors-are-the-same-color
Medium
19 Game Theory https://leetcode.com/problems/cat-and-mouse-ii Hard
20 Game Theory https://leetcode.com/problems/stone-game-ix Medium
21 Game Theory https://leetcode.com/problems/chalkboard-xor-game Hard
 Crack The Coding Interview - Dinesh Varyani
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# Topic Question Difficulty

1 Segment Tree https://leetcode.com/problems/count-of-smaller-numbers-after-self Hard

2 Segment Tree https://leetcode.com/problems/the-skyline-problem Hard
3 Segment Tree https://leetcode.com/problems/number-of-longest-increasing-subsequence Medium
4 Segment Tree https://leetcode.com/problems/range-sum-query-mutable Medium
5 Segment Tree https://leetcode.com/problems/reverse-pairs Hard
6 Segment Tree https://leetcode.com/problems/my-calendar-i Medium
7 Segment Tree https://leetcode.com/problems/count-of-range-sum Hard
8 Segment Tree https://leetcode.com/problems/my-calendar-ii Medium
9 Segment Tree https://leetcode.com/problems/range-module Hard
10 Segment Tree https://leetcode.com/problems/rectangle-area-ii Hard
11 Segment Tree https://leetcode.com/problems/my-calendar-iii Hard
12 Segment Tree https://leetcode.com/problems/create-sorted-array-through-instructions Hard
13 Segment Tree https://leetcode.com/problems/online-majority-element-in-subarray Hard
14 Segment Tree https://leetcode.com/problems/falling-squares Hard
15 Segment Tree https://leetcode.com/problems/minimum-possible-integer-after-at-most-k-adjacent-swaps-on-digits
Hard
16 Segment Tree https://leetcode.com/problems/range-frequency-queries Medium
17 Segment Tree https://leetcode.com/problems/find-a-value-of-a-mysterious-function-closest-to-target
Hard
18 Segment Tree https://leetcode.com/problems/fancy-sequence Hard
19 Segment Tree https://leetcode.com/problems/delivering-boxes-from-storage-to-ports Hard
 Crack The Coding Interview - Dinesh Varyani
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# Topic Question Difficulty

1 Topological Sort https://leetcode.com/problems/course-schedule Medium

2 Topological Sort https://leetcode.com/problems/course-schedule-ii Medium
3 Topological Sort https://leetcode.com/problems/minimum-height-trees Medium
4 Topological Sort https://leetcode.com/problems/longest-increasing-path-in-a-matrix Hard
5 Topological Sort https://leetcode.com/problems/find-eventual-safe-states Medium
6 Topological Sort https://leetcode.com/problems/course-schedule-iv Medium
7 Topological Sort https://leetcode.com/problems/number-of-ways-to-arrive-at-destination Medium
8 Topological Sort https://leetcode.com/problems/rank-transform-of-a-matrix Hard
9 Topological Sort https://leetcode.com/problems/sort-items-by-groups-respecting-dependencies Hard
10 Topological Sort https://leetcode.com/problems/loud-and-rich Medium
11 Topological Sort https://leetcode.com/problems/number-of-restricted-paths-from-first-to-last-nodeMedium
12 Topological Sort https://leetcode.com/problems/largest-color-value-in-a-directed-graph Hard
13 Topological Sort https://leetcode.com/problems/strange-printer-ii Hard
14 Topological Sort https://leetcode.com/problems/find-all-possible-recipes-from-given-supplies Medium
15 Topological Sort https://leetcode.com/problems/parallel-courses-iii Hard
16 Topological Sort https://leetcode.com/problems/count-ways-to-build-rooms-in-an-ant-colony Hard
17 Topological Sort https://leetcode.com/problems/number-of-ways-to-reconstruct-a-tree Hard
 Crack The Coding Interview - Dinesh Varyani
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# Topic Question Difficulty

1 Hash Function https://leetcode.com/problems/subtree-of-another-tree Easy

2 Hash Function https://leetcode.com/problems/maximum-length-of-repeated-subarray Medium
3 Hash Function https://leetcode.com/problems/design-hashmap Easy
4 Hash Function https://leetcode.com/problems/shortest-palindrome Hard
5 Hash Function https://leetcode.com/problems/repeated-dna-sequences Medium
6 Hash Function https://leetcode.com/problems/longest-duplicate-substring Hard
7 Hash Function https://leetcode.com/problems/encode-and-decode-tinyurl Medium
8 Hash Function https://leetcode.com/problems/design-hashset Easy
9 Hash Function https://leetcode.com/problems/check-if-a-string-contains-all-binary-codes-of-size-k
Medium
10 Hash Function https://leetcode.com/problems/longest-happy-prefix Hard
11 Hash Function https://leetcode.com/problems/longest-chunked-palindrome-decomposition Hard
12 Hash Function https://leetcode.com/problems/longest-common-subpath Hard
13 Hash Function https://leetcode.com/problems/distinct-echo-substrings Hard
14 Hash Function https://leetcode.com/problems/delete-duplicate-folders-in-system Hard
15 Hash Function https://leetcode.com/problems/maximum-product-of-the-length-of-two-palindromic-substrings
Hard
 Crack The Coding Interview - Dinesh Varyani
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# Topic Question Difficulty

1 String Matching https://leetcode.com/problems/subtree-of-another-tree Easy

2 String Matching https://leetcode.com/problems/implement-strstr Easy
3 String Matching https://leetcode.com/problems/repeated-substring-pattern Easy
4 String Matching https://leetcode.com/problems/shortest-palindrome Hard
5 String Matching https://leetcode.com/problems/rotate-string Easy
6 String Matching https://leetcode.com/problems/repeated-string-match Medium
7 String Matching https://leetcode.com/problems/longest-happy-prefix Hard
8 String Matching https://leetcode.com/problems/camelcase-matching Medium
9 String Matching https://leetcode.com/problems/string-matching-in-an-array Easy
10 String Matching https://leetcode.com/problems/check-if-a-word-occurs-as-a-prefix-of-any-word-in-a-sentence
Easy
11 String Matching https://leetcode.com/problems/maximum-repeating-substring Easy
12 String Matching https://leetcode.com/problems/find-all-good-strings Hard
13 String Matching https://leetcode.com/problems/form-array-by-concatenating-subarrays-of-another-array
Medium
 Crack The Coding Interview - Dinesh Varyani
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# Topic Question Difficulty

1 Combinatorics https://leetcode.com/problems/unique-paths Medium

2 Combinatorics https://leetcode.com/problems/number-of-music-playlists Hard
3 Combinatorics https://leetcode.com/problems/poor-pigs Hard
4 Combinatorics https://leetcode.com/problems/sum-of-all-subset-xor-totals Easy
5 Combinatorics https://leetcode.com/problems/count-all-valid-pickup-and-delivery-options Hard
6 Combinatorics https://leetcode.com/problems/number-of-ways-to-rearrange-sticks-with-k-sticks-visible
Hard
7 Combinatorics https://leetcode.com/problems/number-of-ways-to-reorder-array-to-get-same-bstHard
8 Combinatorics https://leetcode.com/problems/kth-smallest-instructions Hard
9 Combinatorics https://leetcode.com/problems/vowels-of-all-substrings Medium
10 Combinatorics https://leetcode.com/problems/count-ways-to-build-rooms-in-an-ant-colony Hard
11 Combinatorics https://leetcode.com/problems/probability-of-a-two-boxes-having-the-same-number-of-distinct-balls
Hard
12 Combinatorics https://leetcode.com/problems/minimum-number-of-operations-to-make-string-sorted
Hard
 Crack The Coding Interview - Dinesh Varyani
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# Topic Question Difficulty

1 Binary Indexed Tree https://leetcode.com/problems/count-of-smaller-numbers-after-self Hard

2 Binary Indexed Tree https://leetcode.com/problems/the-skyline-problem Hard
3 Binary Indexed Tree https://leetcode.com/problems/number-of-longest-increasing-subsequence Medium
4 Binary Indexed Tree https://leetcode.com/problems/range-sum-query-mutable Medium
5 Binary Indexed Tree https://leetcode.com/problems/reverse-pairs Hard
6 Binary Indexed Tree https://leetcode.com/problems/count-number-of-teams Medium
7 Binary Indexed Tree https://leetcode.com/problems/count-of-range-sum Hard
8 Binary Indexed Tree https://leetcode.com/problems/create-sorted-array-through-instructions Hard
9 Binary Indexed Tree https://leetcode.com/problems/online-majority-element-in-subarray Hard
10 Binary Indexed Tree https://leetcode.com/problems/find-the-longest-valid-obstacle-course-at-each-position
Hard
11 Binary Indexed Tree https://leetcode.com/problems/queries-on-a-permutation-with-key Medium
12 Binary Indexed Tree https://leetcode.com/problems/minimum-possible-integer-after-at-most-k-adjacent-swaps-on-digits
Hard
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# Topic Question Difficulty

1 Randomized https://leetcode.com/problems/insert-delete-getrandom-o1 Medium

2 Randomized https://leetcode.com/problems/insert-delete-getrandom-o1-duplicates-allowed Hard
3 Randomized https://leetcode.com/problems/linked-list-random-node Medium
4 Randomized https://leetcode.com/problems/random-pick-index Medium
5 Randomized https://leetcode.com/problems/implement-rand10-using-rand7 Medium
6 Randomized https://leetcode.com/problems/shuffle-an-array Medium
7 Randomized https://leetcode.com/problems/random-pick-with-blacklist Hard
8 Randomized https://leetcode.com/problems/random-point-in-non-overlapping-rectangles Medium
9 Randomized https://leetcode.com/problems/generate-random-point-in-a-circle Medium
10 Randomized https://leetcode.com/problems/random-pick-with-weight Medium
11 Randomized https://leetcode.com/problems/random-flip-matrix Medium
12 Randomized https://leetcode.com/problems/best-position-for-a-service-centre Hard
 Crack The Coding Interview - Dinesh Varyani
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# Topic Question Difficulty

1 Data Stream https://leetcode.com/problems/find-median-from-data-stream Hard

2 Data Stream https://leetcode.com/problems/online-stock-span Medium
3 Data Stream https://leetcode.com/problems/kth-largest-element-in-a-stream Easy
4 Data Stream https://leetcode.com/problems/stream-of-characters Hard
5 Data Stream https://leetcode.com/problems/design-browser-history Medium
6 Data Stream https://leetcode.com/problems/product-of-the-last-k-numbers Medium
7 Data Stream https://leetcode.com/problems/number-of-recent-calls Easy
8 Data Stream https://leetcode.com/problems/design-front-middle-back-queue Medium
9 Data Stream https://leetcode.com/problems/stock-price-fluctuation Medium
10 Data Stream https://leetcode.com/problems/design-an-ordered-stream Easy
11 Data Stream https://leetcode.com/problems/sequentially-ordinal-rank-tracker Hard
 Crack The Coding Interview - Dinesh Varyani
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# Topic Question Difficulty

1 Rolling Hash https://leetcode.com/problems/maximum-length-of-repeated-subarray Medium

2 Rolling Hash https://leetcode.com/problems/shortest-palindrome Hard
3 Rolling Hash https://leetcode.com/problems/repeated-dna-sequences Medium
4 Rolling Hash https://leetcode.com/problems/longest-duplicate-substring Hard
5 Rolling Hash https://leetcode.com/problems/check-if-a-string-contains-all-binary-codes-of-size-k
Medium
6 Rolling Hash https://leetcode.com/problems/longest-happy-prefix Hard
7 Rolling Hash https://leetcode.com/problems/longest-chunked-palindrome-decomposition Hard
8 Rolling Hash https://leetcode.com/problems/longest-common-subpath Hard
9 Rolling Hash https://leetcode.com/problems/distinct-echo-substrings Hard
10 Rolling Hash https://leetcode.com/problems/maximum-product-of-the-length-of-two-palindromic-substrings
Hard
 Crack The Coding Interview - Dinesh Varyani
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# Topic Question Difficulty

1 Shortest Path https://leetcode.com/problems/evaluate-division Medium

2 Shortest Path https://leetcode.com/problems/cheapest-flights-within-k-stops Medium
3 Shortest Path https://leetcode.com/problems/network-delay-time Medium
4 Shortest Path https://leetcode.com/problems/path-with-maximum-probability Medium
5 Shortest Path https://leetcode.com/problems/find-the-city-with-the-smallest-number-of-neighbors-at-a-threshold-distance
Medium
6 Shortest Path https://leetcode.com/problems/minimum-cost-to-make-at-least-one-valid-path-in-a-grid
Hard
7 Shortest Path https://leetcode.com/problems/number-of-ways-to-arrive-at-destination Medium
8 Shortest Path https://leetcode.com/problems/number-of-restricted-paths-from-first-to-last-nodeMedium
9 Shortest Path https://leetcode.com/problems/reachable-nodes-in-subdivided-graph Hard
10 Shortest Path https://leetcode.com/problems/second-minimum-time-to-reach-destination Hard
 Crack The Coding Interview - Dinesh Varyani
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# Topic Question Difficulty

1 Monotonic Queue https://leetcode.com/problems/sliding-window-maximum Hard

2 Monotonic Queue https://leetcode.com/problems/maximum-sum-circular-subarray Medium
3 Monotonic Queue https://leetcode.com/problems/shortest-subarray-with-sum-at-least-k Hard
4 Monotonic Queue https://leetcode.com/problems/longest-continuous-subarray-with-absolute-diff-less-than-or-equal-to-limit
Medium
5 Monotonic Queue https://leetcode.com/problems/jump-game-vi Medium
6 Monotonic Queue https://leetcode.com/problems/max-value-of-equation Hard
7 Monotonic Queue https://leetcode.com/problems/constrained-subsequence-sum Hard
8 Monotonic Queue https://leetcode.com/problems/delivering-boxes-from-storage-to-ports Hard
9 Monotonic Queue https://leetcode.com/problems/maximum-number-of-tasks-you-can-assign Hard
 Crack The Coding Interview - Dinesh Varyani
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# Topic Question Difficulty

1 Number Theory https://leetcode.com/problems/count-primes Medium

2 Number Theory https://leetcode.com/problems/add-digits Easy
3 Number Theory https://leetcode.com/problems/x-of-a-kind-in-a-deck-of-cards Easy
4 Number Theory https://leetcode.com/problems/ugly-number-iii Medium
5 Number Theory https://leetcode.com/problems/maximize-score-after-n-operations Hard
6 Number Theory https://leetcode.com/problems/number-of-different-subsequences-gcds Hard
7 Number Theory https://leetcode.com/problems/check-if-it-is-a-good-array Hard
8 Number Theory https://leetcode.com/problems/number-of-pairs-of-interchangeable-rectangles Medium
 Crack The Coding Interview - Dinesh Varyani
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# Topic Question Difficulty

1 Merge Sort https://leetcode.com/problems/merge-k-sorted-lists Hard

2 Merge Sort https://leetcode.com/problems/sort-list Medium
3 Merge Sort https://leetcode.com/problems/count-of-smaller-numbers-after-self Hard
4 Merge Sort https://leetcode.com/problems/reverse-pairs Hard
5 Merge Sort https://leetcode.com/problems/sort-an-array Medium
6 Merge Sort https://leetcode.com/problems/count-of-range-sum Hard
7 Merge Sort https://leetcode.com/problems/create-sorted-array-through-instructions Hard
 Crack The Coding Interview - Dinesh Varyani
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# Topic Question Difficulty

1 Brainteaser https://leetcode.com/problems/divisor-game Easy

2 Brainteaser https://leetcode.com/problems/nim-game Easy
3 Brainteaser https://leetcode.com/problems/bulb-switcher Medium
4 Brainteaser https://leetcode.com/problems/airplane-seat-assignment-probability Medium
5 Brainteaser https://leetcode.com/problems/last-moment-before-all-ants-fall-out-of-a-plank Medium
6 Brainteaser https://leetcode.com/problems/moving-stones-until-consecutive Medium
7 Brainteaser https://leetcode.com/problems/chalkboard-xor-game Hard
 Crack The Coding Interview - Dinesh Varyani
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# Topic Question Difficulty

1 Probability and Statistics https://leetcode.com/problems/new-21-game Medium

2 Probability and Statistics https://leetcode.com/problems/implement-rand10-using-rand7 Medium
3 Probability and Statistics https://leetcode.com/problems/airplane-seat-assignment-probability Medium
4 Probability and Statistics https://leetcode.com/problems/soup-servings Medium
5 Probability and Statistics https://leetcode.com/problems/probability-of-a-two-boxes-having-the-same-number-of-distinct-balls
Hard
6 Probability and Statistics https://leetcode.com/problems/statistics-from-a-large-sample Medium
 Crack The Coding Interview - Dinesh Varyani
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# Topic Question Difficulty

1 Quickselect https://leetcode.com/problems/kth-largest-element-in-an-array Medium

2 Quickselect https://leetcode.com/problems/top-k-frequent-elements Medium
3 Quickselect https://leetcode.com/problems/k-closest-points-to-origin Medium
4 Quickselect https://leetcode.com/problems/wiggle-sort-ii Medium
5 Quickselect https://leetcode.com/problems/find-the-kth-largest-integer-in-the-array Medium
6 Quickselect https://leetcode.com/problems/find-kth-largest-xor-coordinate-value Medium
 Crack The Coding Interview - Dinesh Varyani
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# Topic Question Difficulty

1 Bucket Sort https://leetcode.com/problems/top-k-frequent-elements Medium

2 Bucket Sort https://leetcode.com/problems/top-k-frequent-words Medium
3 Bucket Sort https://leetcode.com/problems/sort-characters-by-frequency Medium
4 Bucket Sort https://leetcode.com/problems/contains-duplicate-iii Medium
5 Bucket Sort https://leetcode.com/problems/maximum-gap Hard
6 Bucket Sort https://leetcode.com/problems/sort-an-array Medium
 Crack The Coding Interview - Dinesh Varyani
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# Topic Question Difficulty

1 Interactive https://leetcode.com/problems/first-bad-version Easy

2 Interactive https://leetcode.com/problems/guess-the-word Hard
3 Interactive https://leetcode.com/problems/find-in-mountain-array Hard
4 Interactive https://leetcode.com/problems/guess-number-higher-or-lower Easy
5 Interactive https://leetcode.com/problems/find-positive-integer-solution-for-a-given-equationMedium
 Crack The Coding Interview - Dinesh Varyani
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# Topic Question Difficulty

1 Doubly-Linked List https://leetcode.com/problems/lru-cache Medium

2 Doubly-Linked List https://leetcode.com/problems/flatten-a-multilevel-doubly-linked-list Medium
3 Doubly-Linked List https://leetcode.com/problems/lfu-cache Hard
4 Doubly-Linked List https://leetcode.com/problems/all-oone-data-structure Hard
5 Doubly-Linked List https://leetcode.com/problems/design-browser-history Medium
 Crack The Coding Interview - Dinesh Varyani
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# Topic Question Difficulty

1 Iterator https://leetcode.com/problems/binary-search-tree-iterator Medium

2 Iterator https://leetcode.com/problems/flatten-nested-list-iterator Medium
3 Iterator https://leetcode.com/problems/iterator-for-combination Medium
4 Iterator https://leetcode.com/problems/peeking-iterator Medium
5 Iterator https://leetcode.com/problems/rle-iterator Medium
 Crack The Coding Interview - Dinesh Varyani
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# Topic Question Difficulty

1 Counting Sort https://leetcode.com/problems/sort-an-array Medium

2 Counting Sort https://leetcode.com/problems/relative-sort-array Easy
3 Counting Sort https://leetcode.com/problems/h-index Medium
4 Counting Sort https://leetcode.com/problems/array-partition-i Easy
5 Counting Sort https://leetcode.com/problems/height-checker Easy
 Crack The Coding Interview - Dinesh Varyani
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# Topic Question Difficulty

1 Reservoir Sampling https://leetcode.com/problems/linked-list-random-node Medium

2 Reservoir Sampling https://leetcode.com/problems/random-pick-index Medium
3 Reservoir Sampling https://leetcode.com/problems/random-point-in-non-overlapping-rectangles Medium
4 Reservoir Sampling https://leetcode.com/problems/random-flip-matrix Medium
 Crack The Coding Interview - Dinesh Varyani
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# Topic Question Difficulty

1 Line Sweep https://leetcode.com/problems/the-skyline-problem Hard

2 Line Sweep https://leetcode.com/problems/rectangle-area-ii Hard
3 Line Sweep https://leetcode.com/problems/perfect-rectangle Hard
4 Line Sweep https://leetcode.com/problems/minimum-interval-to-include-each-query Hard
 Crack The Coding Interview - Dinesh Varyani
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# Topic Question Difficulty

1 Suffix Array https://leetcode.com/problems/longest-duplicate-substring Hard

2 Suffix Array https://leetcode.com/problems/longest-common-subpath Hard
3 Suffix Array https://leetcode.com/problems/number-of-ways-to-separate-numbers Hard
 Crack The Coding Interview - Dinesh Varyani
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# Topic Question Difficulty

1 Eulerian Circuit https://leetcode.com/problems/reconstruct-itinerary Hard

2 Eulerian Circuit https://leetcode.com/problems/valid-arrangement-of-pairs Hard
3 Eulerian Circuit https://leetcode.com/problems/cracking-the-safe Hard
 Crack The Coding Interview - Dinesh Varyani
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# Topic Question Difficulty

1 Minimum Spanning Tree https://leetcode.com/problems/min-cost-to-connect-all-points Medium

2 Minimum Spanning Tree https://leetcode.com/problems/find-critical-and-pseudo-critical-edges-in-minimum-spanning-tree
Hard
 Crack The Coding Interview - Dinesh Varyani
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# Topic Question Difficulty

1 Rejection Sampling https://leetcode.com/problems/implement-rand10-using-rand7 Medium

2 Rejection Sampling https://leetcode.com/problems/generate-random-point-in-a-circle Medium
 Crack The Coding Interview - Dinesh Varyani
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# Topic Question Difficulty

1 Strongly Connected Component https://leetcode.com/problems/find-critical-and-pseudo-critical-edges-in-minimum-spanning-tree

Hard
2 Strongly Connected Component https://leetcode.com/problems/minimum-number-of-days-to-disconnect-island Hard
 Crack The Coding Interview - Dinesh Varyani
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# Topic Question Difficulty

1 Radix Sort https://leetcode.com/problems/maximum-gap Hard

2 Radix Sort https://leetcode.com/problems/sort-an-array Medium
 Crack The Coding Interview - Dinesh Varyani
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# Topic Question Difficulty

1 Biconnected Component https://leetcode.com/problems/critical-connections-in-a-network Hard