Tree in data structure What is tree ?

What is tree 

Definition:-  Tree is  is hierarchical (or non-linear) data structure.

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Tree is a finite set of elements that is either empty or partitioned into three  disjoint subsets ,the first subset contains a single element called the  root of the tree.The other two subset are themselves tree called left and right subtree  of original tree .Each element of tree is called a node of the tree .

Important Term related with trees-

Root Node-  The First Subset or single element called root or parent node  of the tree (Such as A is the root node in above figure)

Leaf Node -  The node that has no son is called  leaf node of tree (Such as D,E,F,G are the leaf node in above fig)

Sibling- Two nodes are sibling if they have same parent (such as D,E and F,G are siblings)

Level of tree-  The level of  a node in binary tree is the number of edges  traversed from the root node to the node i.e. root has 0 level and level of any other node is one more than the level of its parents (such as level of below tree is 3 )

 

Depth of Tree-    The depth of tree is the maximum level of any leaf  in the tree ( such as depth of below tree is 4)

Climbing-  Going from the leaves to the root is called "climbing"

Descending - Going from the root  to the leaves is called descending 

Types of Tree in data structure -Binary Tree Lecture 2