Find Bottom Left Tree Value

513. Find Bottom Left Tree Value

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.

/**
 * Definition for a binary tree node.
 * public class TreeNode {
 *     int val;
 *     TreeNode left;
 *     TreeNode right;
 *     TreeNode(int x) { val = x; }
 * }
 */
public class Solution {
    public int findBottomLeftValue(TreeNode root) {
        if (root == null) {
            return 0;
        }
        
        Queue<TreeNode> queue = new LinkedList<>();
        queue.offer(root);
        
        int result = 0;
        
        while (!queue.isEmpty()) {
            TreeNode node = queue.poll();
            result = node.val;
                
            if (node.right != null) {
                queue.offer(node.right);
            }
            if (node.left != null) {
                queue.offer(node.left);
            }
        }
        
        return result;
    }
}

Hope this helps,
Michael