Maximum Depth of Binary Tree

public class Solution {public static void main(String[] args) {// TODO Auto-generated method stub}public int maxDepth(TreeNode root) {        if(root == null)        return 0;        int left = depth(root.left);        int right = depth(root.right);        return Math.max(left, right)+1;    }public int depth(TreeNode node)//得到左右子树的最大深度{if(node == null)return 0;int leftdepth = depth(node.left);int rightdepth = depth(node.right);return Math.max(leftdepth, rightdepth)+1;}}class TreeNode {    int val;    TreeNode left;    TreeNode right;    TreeNode(int x)    {    val = x;    }}