[LeetCode][Java]Maximum Depth of Binary Tree

 1 /**
 2  * Definition for binary tree
 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 maxDepth(TreeNode root) {
12         if (root == null){
13             return 0;
14 　　　　 }
15         int leftDepth = maxDepth(root.left);
16         int rightDepth = maxDepth(root.right);
17         return Math.max(leftDepth, rightDepth) + 1;
18     }
19 }