Tree
Tree is a infinite set of nodes with one
specially designated node called the
“root” and the remaining node are
partitioned into disjoints sets T1 to Tn,
where each of those sets is a TREE.
T1 to Tn are called sub-trees of the
root
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    Terms used with trees
Node: A item storing information and
branches to other nodes
Null Tree: Tree with no node
Leaf Node: Terminal node of a tree & does
not have any node connected to it
Degree of a Node: No of sub trees of a node
Degree of a tree: Degree of a tree is
maximum degree of a node in the tree
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      Terms used in trees
Parent Node: node having other nodes
connected to it
Siblings: Children of the same parents
Descendants: all those node which are
reachable from that node
Ancestor: all the node along the path from
the root to that node
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      Terms used in Trees
Level of a Node:
  Indicates the position of the node in the
   hierarchy
  Level of any node is level of its parent +1
  Level of root is 0
Depth of a tree: maximum level of any node
in the tree
Traversal : Visiting each node of tree exactly
once
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    Binary Tree Traversal
In-order  L V R
Pre-Order  V L R
Post-Order  L R V
The traversal algorithms can be
implemented easily using recursion.
Non-recursive algorithms for
implementing traversal needs stack to
store node pointers.
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100,50,125,75,135,25,85,45,115,130,128
in-25,45,50,75,85,100,115,125,128,130,135
pre-100,50,25,45,75,85,125,115,135,130,128
post45,25,85,75,50,115,128,130,135,125,100
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          Types of Trees
Binary Trees: It is a finite set of nodes
partitioned into three sub sets:- Root, Left
sub tree, Right sub tree
Binary Search tree: A binary search tree is a
binary tree in which the nodes are arranged
according to their values
Strictly Binary tree: All non leaf node have
two branches
Complete Binary tree: Tree with all leaf
nodes at the sameSunbeam
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        Complete Binary Tree
            A                                              A
                                                   B           C
    B               C
                                               D                   E
D       F       G       E
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                Strictly Binary Tree
                A                                          A
        B           C                              B           C
    D       I       J   E                      D                   E
            F       G        H                         F
K
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           Types of trees
Skewed Binary tree: The branches of this
tree have either only left branches or right
branches
Almost Complete Binary Tree: A Binary
Tree of depth d is said to be an Almost
Complete Binary Tree if:
  Each leaf in a tree is at level d or d-1
  For any node N1 in a tree with right
   descendent at level d , N1 must have Son
   and every left descendant of N1 should be
   either a leaf or should         have two sons
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            Almost complete binary tree
                A                        A                                     A
        B           C           B                                      B
                                                       C                               C
    D           E           D           E          F       G       D           E   F        G
F           G           H           I          J           K   H           I
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