leetcode104——Maximum Depth of Binary Tree

题目大意：求二叉树的深度

分析：简单dfs

代码：

/**
 * Definition for a binary tree node.
 * struct TreeNode {
 *     int val;
 *     TreeNode *left;
 *     TreeNode *right;
 *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
 * };
 */
class Solution {
public:
int maxDepth(TreeNode* root) {
if (root == NULL)
return 0;
                return max(maxDepth(root->left),maxDepth(root->right)) + 1;
}
};