Check the review of this SDE sheet at Striver’s instagram story highlights.
Instagram id: Striver_79
To know the entire list and other stuffs like Projects, Resume, how to give
interviews….watch the entire video at:
https://www.youtube.com/watch?v=WNtzUR_MwUQ
Find the placement series at: https://www.youtube.com/watch?
v=c0_1QnyVYQY&list=PLgUwDviBIf0p4ozDR_kJJkONnb1wdx2Ma&index=1
Subscribe to the channel. :) (take U forward) (striver_79)
(Channel run by ex-Amazon | Media.net(Directi) | GFG) employee, CM at Codeforces and 6*
at Codechef)
Only start doing these problems if you feel you are comfortable with solving basic problems
of DSA. Once you are, you can start preparing for these problems, because these problems
are solely interview based.
Day1: (Arrays)
1. Sort an array of 0’s 1’s 2’s without using extra space or sorting algo
https://www.youtube.com/watch?v=oaVa-
9wmpns&list=PLgUwDviBIf0rPG3Ictpu74YWBQ1CaBkm2&index=2 (Problem link in
description)
2. Repeat and Missing Number
https://www.youtube.com/watch?
v=5nMGY4VUoRY&list=PLgUwDviBIf0rPG3Ictpu74YWBQ1CaBkm2&index=3
(Problem link in description)
3. Merge two sorted Arrays without extra space
https://www.youtube.com/watch?
v=hVl2b3bLzBw&list=PLgUwDviBIf0rPG3Ictpu74YWBQ1CaBkm2&index=4
(Problem link in description)
4. Kadane’s Algorithm
https://www.youtube.com/watch?
v=w_KEocd__20&list=PLgUwDviBIf0rPG3Ictpu74YWBQ1CaBkm2&index=5
5. Merge Overlapping Subintervals
https://www.youtube.com/watch?
v=2JzRBPFYbKE&list=PLgUwDviBIf0rPG3Ictpu74YWBQ1CaBkm2&index=6
6. Find the duplicate in an array of N+1 integers.
(Ignore the video quality, as this was the first video which i recorded)
https://www.youtube.com/watch?
v=32Ll35mhWg0&list=PLgUwDviBIf0rPG3Ictpu74YWBQ1CaBkm2&index=1
Day2: (Arrays)
1. Set Matrix Zeros
(https://www.youtube.com/watch?
v=M65xBewcqcI&list=PLgUwDviBIf0rPG3Ictpu74YWBQ1CaBkm2&index=7)
2. Pascal Triangle
https://www.youtube.com/watch?
v=6FLvhQjZqvM&list=PLgUwDviBIf0rPG3Ictpu74YWBQ1CaBkm2&index=8
3. Next Permutation
https://www.youtube.com/watch?
v=LuLCLgMElus&list=PLgUwDviBIf0rPG3Ictpu74YWBQ1CaBkm2&index=9
4. Inversion of Array (Using Merge Sort)
https://www.youtube.com/watch?v=kQ1mJlwW-
c0&list=PLgUwDviBIf0rPG3Ictpu74YWBQ1CaBkm2&index=10
5. Stock Buy and Sell
https://www.youtube.com/watch?
v=eMSfBgbiEjk&list=PLgUwDviBIf0rPG3Ictpu74YWBQ1CaBkm2&index=11
6. Rotate Matrix
https://www.youtube.com/watch?
v=Y72QeX0Efxw&list=PLgUwDviBIf0rPG3Ictpu74YWBQ1CaBkm2&index=12
Day3: (Arrays/maths)
1. Search in a 2D matrix
https://www.youtube.com/watch?
v=ZYpYur0znng&list=PLgUwDviBIf0rPG3Ictpu74YWBQ1CaBkm2&index=13
2. Pow(X,n)
https://www.youtube.com/watch?
v=l0YC3876qxg&list=PLgUwDviBIf0rPG3Ictpu74YWBQ1CaBkm2&index=14
3. Majority Element (>N/2 times) https://www.youtube.com/watch?
v=AoX3BPWNnoE&list=PLgUwDviBIf0rPG3Ictpu74YWBQ1CaBkm2&index=15
4. Majority Element (>N/3 times)
https://www.youtube.com/watch?
v=yDbkQd9t2ig&list=PLgUwDviBIf0rPG3Ictpu74YWBQ1CaBkm2&index=16
5. Grid Unique Paths
https://www.youtube.com/watch?
v=t_f0nwwdg5o&list=PLgUwDviBIf0rPG3Ictpu74YWBQ1CaBkm2&index=17
6. Reverse Pairs (Leetcode)
https://www.youtube.com/watch?
v=S6rsAlj_iB4&list=PLgUwDviBIf0rPG3Ictpu74YWBQ1CaBkm2&index=18
7. Go through Puzzles from GFG (Search on own)
Day4: (Hashing)
1. 2 Sum problem
https://www.youtube.com/watch?
v=dRUpbt8vHpo&list=PLgUwDviBIf0rVwua0kKYlsS_ik_1lyVK_&index=1
2. 4 Sum problem
https://www.youtube.com/watch?
v=4ggF3tXIAp0&list=PLgUwDviBIf0p4ozDR_kJJkONnb1wdx2Ma&index=20
3. Longest Consecutive Sequence
https://www.youtube.com/watch?
v=qgizvmgeyUM&list=PLgUwDviBIf0p4ozDR_kJJkONnb1wdx2Ma&index=21
4. Largest Subarray with 0 sum
https://www.youtube.com/watch?
v=xmguZ6GbatA&list=PLgUwDviBIf0p4ozDR_kJJkONnb1wdx2Ma&index=22
5. Count number of subarrays with given XOR(this clears a lot of problems)
https://www.youtube.com/watch?
v=lO9R5CaGRPY&list=PLgUwDviBIf0p4ozDR_kJJkONnb1wdx2Ma&index=23
6. Longest substring without repeat
https://www.youtube.com/watch?v=qtVh-
XEpsJo&list=PLgUwDviBIf0p4ozDR_kJJkONnb1wdx2Ma&index=25
Day5: (LinkedList)
1. Reverse a LinkedList
https://www.youtube.com/watch?v=iRtLEoL-r-
g&list=PLgUwDviBIf0p4ozDR_kJJkONnb1wdx2Ma&index=26
2. Find middle of LinkedList
https://www.youtube.com/watch?v=sGdwSH8RK-
o&list=PLgUwDviBIf0p4ozDR_kJJkONnb1wdx2Ma&index=27
3. Merge two sorted Linked List
https://www.youtube.com/watch?
v=Xb4slcp1U38&list=PLgUwDviBIf0p4ozDR_kJJkONnb1wdx2Ma&index=28
4. Remove N-th node from back of LinkedList
https://www.youtube.com/watch?v=Lhu3MsXZy-
Q&list=PLgUwDviBIf0p4ozDR_kJJkONnb1wdx2Ma&index=29
5. Delete a given Node when a node is given. (0(1) solution)
https://www.youtube.com/watch?
v=icnp4FJdZ_c&list=PLgUwDviBIf0p4ozDR_kJJkONnb1wdx2Ma&index=30
6. Add two numbers as LinkedList
https://www.youtube.com/watch?
v=LBVsXSMOIk4&list=PLgUwDviBIf0p4ozDR_kJJkONnb1wdx2Ma&index=31
Day6:
1. Find intersection point of Y LinkedList
https://www.youtube.com/watch?
v=u4FWXfgS8jw&list=PLgUwDviBIf0p4ozDR_kJJkONnb1wdx2Ma&index=32
2. Detect a cycle in Linked List
https://www.youtube.com/watch?
v=354J83hX7RI&list=PLgUwDviBIf0p4ozDR_kJJkONnb1wdx2Ma&index=33
3. Reverse a LinkedList in groups of size k.
https://www.youtube.com/watch?
v=Of0HPkk3JgI&list=PLgUwDviBIf0p4ozDR_kJJkONnb1wdx2Ma&index=33
4. Check if a LinkedList is palindrome or not.
https://www.youtube.com/watch?v=-
DtNInqFUXs&list=PLgUwDviBIf0p4ozDR_kJJkONnb1wdx2Ma&index=35
5. Find the starting point of the Loop of LinkedList
https://www.youtube.com/watch?
v=QfbOhn0WZ88&list=PLgUwDviBIf0p4ozDR_kJJkONnb1wdx2Ma&index=36
6. Flattening of a LinkedList
https://www.youtube.com/watch?
v=ysytSSXpAI0&list=PLgUwDviBIf0p4ozDR_kJJkONnb1wdx2Ma&index=37
7. Rotate a LinkedList
https://www.youtube.com/watch?
v=9VPm6nEbVPA&list=PLgUwDviBIf0p4ozDR_kJJkONnb1wdx2Ma&index=38
Day7: (2-pointer)
1. Clone a Linked List with random and next pointer
https://www.youtube.com/watch?
v=VNf6VynfpdM&list=PLgUwDviBIf0p4ozDR_kJJkONnb1wdx2Ma&index=39
2. 3 sum
https://www.youtube.com/watch?
v=onLoX6Nhvmg&list=PLgUwDviBIf0p4ozDR_kJJkONnb1wdx2Ma&index=40
3. Trapping rainwater
https://www.youtube.com/watch?
v=m18Hntz4go8&list=PLgUwDviBIf0p4ozDR_kJJkONnb1wdx2Ma&index=41
4. Remove Duplicate from Sorted array
https://www.youtube.com/watch?
v=Fm_p9lJ4Z_8&list=PLgUwDviBIf0p4ozDR_kJJkONnb1wdx2Ma&index=42
5. Max consecutive ones
https://www.youtube.com/watch?
v=Mo33MjjMlyA&list=PLgUwDviBIf0p4ozDR_kJJkONnb1wdx2Ma&index=43
Day8: (Greedy)
1. N meeting in one room
https://www.youtube.com/watch?
v=II6ziNnub1Q&list=PLgUwDviBIf0p4ozDR_kJJkONnb1wdx2Ma&index=44
2. Minimum number of platforms required for a railway
https://www.youtube.com/watch?
v=dxVcMDI7vyI&list=PLgUwDviBIf0p4ozDR_kJJkONnb1wdx2Ma&index=45
3. Job sequencing Problem
https://www.youtube.com/watch?
v=LjPx4wQaRIs&list=PLgUwDviBIf0p4ozDR_kJJkONnb1wdx2Ma&index=46
4. Fractional Knapsack Problem
https://www.youtube.com/watch?
v=F_DDzYnxO14&list=PLgUwDviBIf0p4ozDR_kJJkONnb1wdx2Ma&index=48
5. Greedy algorithm to find minimum number of coins
https://www.youtube.com/watch?
v=mVg9CfJvayM&list=PLgUwDviBIf0p4ozDR_kJJkONnb1wdx2Ma&index=47
6. Activity Selection (it is same as N meeting in one room)
https://www.youtube.com/watch?
v=II6ziNnub1Q&list=PLgUwDviBIf0p4ozDR_kJJkONnb1wdx2Ma&index=44
Day9 (Recursion):
1. Subset Sums
https://www.youtube.com/watch?
v=rYkfBRtMJr8&list=PLgUwDviBIf0p4ozDR_kJJkONnb1wdx2Ma&index=52
2. Subset-II
https://www.youtube.com/watch?
v=RIn3gOkbhQE&list=PLgUwDviBIf0p4ozDR_kJJkONnb1wdx2Ma&index=53
3. Combination sum-1
https://www.youtube.com/watch?
v=OyZFFqQtu98&list=PLgUwDviBIf0p4ozDR_kJJkONnb1wdx2Ma&index=49
4. Combination sum-2
https://www.youtube.com/watch?
v=G1fRTGRxXU8&list=PLgUwDviBIf0p4ozDR_kJJkONnb1wdx2Ma&index=50
5. Palindrome Partitioning
https://www.youtube.com/watch?
v=WBgsABoClE0&list=PLgUwDviBIf0p4ozDR_kJJkONnb1wdx2Ma&index=51
6. K-th permutation Sequence
https://www.youtube.com/watch?
v=wT7gcXLYoao&list=PLgUwDviBIf0p4ozDR_kJJkONnb1wdx2Ma&index=55
Day10: (Recursion and Backtracking)
1. Print all Permutations of a string/array
2. N queens Problem
3. Sudoku
4. M coloring Problem (Graph prob)
5. Rat in a Maze
6. Word Break (print all ways)
Day11: (Divide and Conquer)
1. 1/N-th root of an integer (use binary search) (square root, cube root, ..)
2. Matrix Median
3. Find the element that appears once in sorted array, and rest element appears twice
(Binary search)
4. Search element in a sorted and rotated array/ find pivot where it is rotated
5. Median of 2 sorted arrays
6. K-th element of two sorted arrays
Day12: (Bits) (Optional, very rare topic in interviews, but if you have time left, someone might
ask)
1. Check if a number if a power of 2 or not in O(1)
2. Count total set bits O(logn) gfg
3. Divide Integers without / operator
4. Power Set (this is very important)
5. Find MSB in o(1)
6. Find square of a number without using multiplication or division operators.
Day13: (Stack and Queue)
1. Implement Stack / Implement Queue
2. BFS
3. Implement Stack using Queue
4. Implement Queue using Stack
5. Check for balanced parentheses
6. Next Greater Element
Day14:
1. Next Smaller Element
2. LRU cache (vvvv. imp)
3. Largest rectangle in histogram
4. Sliding Window maximum
5. Implement Min Stack
6. Rotten Orange (Using BFS)
Day15: (String)
1. Reverse Words in a String
2. Longest Palindrome in a string
3. Roman Number to Integer and vice versa
4. Implement ATOI/STRSTR
5. Longest Common Prefix
6. Rabin Karp
Day16: (String)
1. Prefix Function/Z-Function
2. KMP algo
3. Minimum characters needed to be inserted in the beginning to make it palindromic.
4. Check for Anagrams
5. Count and Say
6. Compare version numbers
Day17: (Binary Tree)
1. Inorder Traversal (with recursion and without recursion)
2. Preorder Traversal (with recursion and without recursion)
3. Postorder Traversal (with recursion and without recursion)
4. LeftView Of Binary Tree
5. Bottom View of Binary Tree
6. Top View of Binary Tree
Day18: (Binary Tree)
1. Level order Traversal / Level order traversal in spiral form
2. Height of a Binary Tree
3. Diameter of Binary Tree
4. Check if Binary tree is height balanced or not
5. LCA in Binary Tree
6. Check if two trees are identical or not
Day 19: (Binary Tree)
1. Maximum path sum
2. Construct Binary Tree from inorder and preorder
3. Construct Binary Tree from Inorder and Postorder
4. Symmetric Binary Tree
5. Flatten Binary Tree to LinkedList
6. Check if Binary Tree is mirror of itself or not
Day 20: (Binary Search Tree)
1. Populate Next Right pointers of Tree
2. Search given Key in BST
3. Construct BST from given keys.
4. Check is a BT is BST or not
5. Find LCA of two nodes in BST
6. Find the inorder predecessor/successor of a given Key in BST.
Day21: (BinarySearchTree)
1. Floor and Ceil in a BST
2. Find K-th smallest and K-th largest element in BST (2 different Questions)
3. Find a pair with a given sum in BST
4. BST iterator
5. Size of the largest BST in a Binary Tree
6. Serialize and deserialize Binary Tree
Day22: (Mixed Questions)
1. Binary Tree to Double Linked List
2. Find median in a stream of running integers.
3. K-th largest element in a stream.
4. Distinct numbers in Window.
5. K-th largest element in an unsorted array.
6. Flood-fill Algorithm
Day23: (Graph)
1. Clone a graph (Not that easy as it looks)
2. DFS
3. BFS
4. Detect A cycle in Undirected Graph/Directed Graph
5. Topo Sort
6. Number of islands (Do in Grid and Graph both)
7. Bipartite Check
Day24: (Graph)
1. SCC(using KosaRaju’s algo)
2. Djisktra’s Algorithm
3. Bellman Ford Algo
4. Floyd Warshall Algorithm
5. MST using Prim’s Algo
6. MST using Kruskal’s Algo
Day25: (Dynamic Programming)
1. Max Product Subarray
2. Longest Increasing Subsequence
3. Longest Common Subsequence
4. 0-1 Knapsack
5. Edit Distance
6. Maximum sum increasing subsequence
7. Matrix Chain Multiplication
Day26: (DP)
1. Maximum sum path in matrix, (count paths, and similar type do, also backtrack to find
the maximum path)
2. Coin change
3. Subset Sum
4. Rod Cutting
5. Egg Dropping
6. Word Break
7. Palindrome Partitioning (MCM Variation)
8. Maximum profit in Job scheduling
Day27:
1. Revise OS notes that you would have made during your sem
2. If not made notes, spend 2 or 3 days and make notes from Knowledge Gate.
Day28:
1. Revise DBMS notes that you would have made during your semesters.
2. If not made notes, spend 2 or 3 days and make notes from Knowledge Gate.
Day29:
1. Revise CN notes, that you would have made during your sem.
2. If not made notes, spend 2 or 3 days and make notes from Knowledge Gate.
Day30:
1. Make a note of how will your represent your projects, and prepare all questions
related to tech which you have used in your projects. Prepare a note which you can
say for 3-10 minutes when he asks you that say something about the project.
Hurrah!! You are ready for your placement after a month of hard-work without a cheat day.
