# Description

Given a binary tree, find its minimum depth.

The minimum depth is the number of nodes along the shortest path from the root node down to the nearest leaf node.

The original problem is here.

The original code is here.

# My Solution

I solve this problem in C++, as below:

``````/*
*Minimum Depth of Binary Tree
*Author: shuaijiang
*Email: zhaoshuaijiang8@gmail.com
*/
#include<iostream>
#include<math.h>
#include<stdlib.h>
using namespace std;

/**
* 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 minDepth(TreeNode* root) {
if(root==NULL)
return 0;
if(root->left!=NULL && root->right==NULL)
return 1+minDepth(root->left);
if(root->left==NULL && root->right!=NULL)
return 1+minDepth(root->right);

return min(1+minDepth(root->left),1+minDepth(root->right));
}
};
``````

# Note

In the solution, recursion is needed.