Find Bottom Left Tree Value is an example of null problems. In this post we will see how we can solve in Javascript.

Problem Description

Given a binary tree, find the leftmost value in the last row of the tree.

Example 1

Input:

  2
 / \
1   3

Output: 1

Example 2

Input:

    1
   / \
  2   3
 /   / \
4   5   6
   /
  7

Output: 7

Note: You may assume the tree (i.e., the given root node) is not NULL.

Implementation: Please check the main.js snippet for the solution.  If you have different approach in mind or have any suggestion for this implementation feel free to share in the comment below. Thanks!