176. Find the Size of a Binary Tree without Recursion

Objective: Given a binary tree, Write a non-recursive algorithm to find the size of the tree.

Note : Size of the tree is num­ber of nodes in the tree

Approach:

In our earlier post (link) we have seen the clean and simple recursive approach for finding the size of the tree. Now we will see how to solve it without recursion.

If we are not using recursion then we need a data structure to store the tree traversal, we will use queue here.

Solution is exactly similar to tree traversal without recursion. Just that we will keep counting the number of nodes.

Output:

Tree Size: 5

Related Problems:

- In a Binary Tree, Create Linked Lists of all the nodes at each depth Hard
- Check the completeness of given binary tree | Set 1 - Using Node Count Medium
- Find Nodes X Levels Up from Leaf Nodes in a Tree Medium
- Construct a Binary Tree from Given Inorder and Depth-First-Search Hard
- Binary Tree - Preorder Traversal - Non Recursive Approach Beginner