142. Locate the Farthest Left Node on the Bottom Level

Objective: - Given a binary tree, Find the deepest left node in it.

Approach:

• This approach is similar to "Find the Deepest Node in a Binary Tree" with little modification.
• Take two global variables as deepestlevel and deepLeftNode.
• starting with level=0, Do the inorder traversal and whenever you go down one level ( root.left OR root.right), increase the level by 1.
• Keep checking if the current node is the left child and deepestlevel < level, if yes then update the deepestlevel and deepLeftNode.
• At the end return " deepLeftNode ", which will be the deepest node value.
• See the code for a better explanation.

Output:

Deepest Left child is: 4

Approach: - Without using global variables

We will keep track of the deepest left node and pass it along during recursion. Will take the Result object ( with data and level). See the code below for more understanding.

Output:

Deepest Left child is: 18

Related Problems:

- Find Paths with Sum in Binary Tree Medium
- In a Binary Tree, Check if Two nodes has the same parent or are siblings Medium
- In a Binary Tree, Create Linked Lists of all the nodes at each depth Hard
- Maximum Subarray OR Largest Sum Contiguous Subarray Problem – Divide and Conquer Hard
- Level Order Traversal, Print each level in separate line Medium