LeetCode 刷题之二：寻找二叉树的最大深度

题目为：

Given a binary tree, find its maximum depth.

The maximum depth is the number of nodes along the longest path from the root node down to the farthest leaf node.

阶梯思路：对于这种题目最简单的方法就是递归操作了

代码为：

/** * Definition for binary tree * public class TreeNode { *     int val; *     TreeNode left; *     TreeNode right; *     TreeNode(int x) { val = x; } * } */public class Solution {    public int maxDepth(TreeNode root) {        if(root == null)            return 0;       else if(root.left == null && root.right == null)            return 1;       else            {                int leftDepth= maxDepth(root.left);       int rightDepth = maxDepth(root.right);                if(leftDepth > rightDepth)                    return leftDepth +1;                else                    return rightDepth +1;             }           }}