LinCode Maximum Depth of Binary Tree 二叉树的最大深度

中文版：

给定一个二叉树，找出其最大深度。

二叉树的深度为根节点到最远叶子节点的距离。

样例

给出一棵如下的二叉树:

1

/ \

2 3

/ \

4 5

这个二叉树的最大深度为3.

English Version:

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.

Example

Given a binary tree as follow:

1

/ \

2 3

/ \

4 5

The maximum depth is 3.

/**
* Definition of TreeNode:
* public class TreeNode {
*     public int val;
*     public TreeNode left, right;
*     public TreeNode(int val) {
*         this.val = val;
*         this.left = this.right = null;
*     }
* }
*/
public class Solution {
/**
* @param root: The root of binary tree.
* @return: An integer.
*/
public int maxDepth(TreeNode root) {
if(root == null) return 0;
return Math.max(maxDepth(root.left),maxDepth(root.right)) + 1;
}
}