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.

代码如下：

/**
 * 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;
       int depth = 1;
       Depth(root,depth,1);
       return depth;
    }
    
    void Depth(TreeNode* root,int& depth,int count)
    {
        if(root == NULL)
            return;
            
        if(count > depth)
            depth = count;
        
        Depth(root->left,depth,count+1);
        Depth(root->right,depth,count+1);
    }
};