Define:

(i) Tree

(ii) Binary Tree

(iii) Extended Binary

#### Solution

(i)**Tree**:Tree is a hierarchical data structure. A tree is a finite set of nodes that has a distinguished node called the root node. Remaining nodes of the tree forms disjoint sets of nodes. These sets are again trees. Each of which is called subtree of root node.

(ii) **Binary Tree**:A binary tree is a tree in which every node can have at the most two children.

It is a finite set of elements called nodes such that either

Tree is empty or

It contains a root node R and remaining nodes forms two sets of disjoint binary trees called left subtree and right subtree of R.

So a binary tree may be either empty or contains a distinguished node called root node. Root node is the top most node of the tree. If there are more than one node then remaining nodes belong to either left or the right subtree of root node

(iii)** Extended Binary: **An extended Binary tree is a special form of a binary tree. A binary tree will be an extended binary tree if it strictly has either zero or two children. They are also called as Strict Binary Tree or Two-Tree.