[LeetCode]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.

思考：DFS。

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