1 /** 2  * Definition for a binary tree node. 3  * public class TreeNode { 4  *     int val; 5  *     TreeNode left; 6  *     TreeNode right; 7  *     TreeNode(int x) { val = x; } 8  * } 9  */10 public class Solution {11     public int findBottomLeftValue(TreeNode root) {12         Deque
     
       row = new LinkedList
      
       ();13         row.add(root);14         int ans = 0;15         while (row.isEmpty() != true) {16             int size = row.size();17             for (int i = 0; i < size; i++) {18                 TreeNode node = row.poll();19                 if (i == 0) ans = node.val;20                 if (node.left != null) row.add(node.left);21                 if (node.right != null) row.add(node.right);22             }23         }24         return ans;25     }26 }