【leetcode】104. Maximum Depth of Binary Tree

题目要求：

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.

即给定一个二叉树，求它的最大深度

思路：递归求左子树和右子树的深度，然后返回较大者

/**
* Definition for a binary tree node.
* 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;
}
int left = maxDepth(root.left);
int right = maxDepth(root.right);
return (left>right?left:right)+1;
}
}