Maximum Depth of Binary Tree

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.

求二叉树的最大深度。

思路：求每个节点的左子树深度和有子树深度，返回比较大的值。

/** * 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) {        int left;        int right;        if(root == null) {            return 0;        } else {            left = maxDepth(root.left);            right = maxDepth(root.right);            if(left > right) {                return left+1;            } else {                return right+1;            }        }    }}