LeetCode 104. Maximum Depth of Binary Tree （二叉树的最大深度）

 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 {
12     public int maxDepth(TreeNode root) 
13     {
14         int depth = 0;
15         
16         if(root == null)
17             return depth;
18         
19         
20         depth = Math.max(maxDepth(root.left), maxDepth(root.right));
21         
22         
23         return depth + 1;
24     }
25 }