maximum-depth-of-binary-tree

题目：

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.

程序：

class Solution {public:    int maxDepth(TreeNode *root) {        if(root==NULL)            return 0;        int h1=0,h2=0;        if(root->left)            h1=maxDepth(root->left);        if(root->right)            h2=maxDepth(root->right);        return h1>h2?h1+1:h2+1;    }};