# Minimum Depth of Binary Tree – Leetcode Solution

In this post, we are going to solve the 111. Minimum Depth of Binary Tree problem of Leetcode. This problem 111. Minimum Depth of Binary Tree is a Leetcode easy level problem. Let’s see the code, 111. Minimum Depth of Binary Tree – Leetcode Solution.

## Problem

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.

Note: A leaf is a node with no children.

### Example 1 :

``````Input: root = [3,9,20,null,null,15,7]
Output: 2``````

### Example 2 :

``````Input: root = [2,null,3,null,4,null,5,null,6]
Output: 5``````

### Constraints

• The number of nodes in the tree is in the range `[0, 105]`.
• `-1000 <= Node.val <= 1000`

Now, let’s see the code of 111. Minimum Depth of Binary Tree – Leetcode Solution.

# Minimum Depth of Binary Tree – Leetcode Solution

### 111. Minimum Depth of Binary Tree – Solution in Java

```/**
* Definition for a binary tree node.
* public class TreeNode {
*     int val;
*     TreeNode left;
*     TreeNode right;
*     TreeNode() {}
*     TreeNode(int val) { this.val = val; }
*     TreeNode(int val, TreeNode left, TreeNode right) {
*         this.val = val;
*         this.left = left;
*         this.right = right;
*     }
* }
*/
class Solution {
public int minDepth(TreeNode root) {
if(root == null) return 0;
int left = minDepth(root.left);
int right = minDepth(root.right);

return (left == 0 || right == 0) ? left + right + 1 : Math.min(left,right)+1;
}
}```

### 111. Minimum Depth of Binary Tree – Solution in C++

```/**
* Definition for a binary tree node.
* struct TreeNode {
*     int val;
*     TreeNode *left;
*     TreeNode *right;
*     TreeNode() : val(0), left(nullptr), right(nullptr) {}
*     TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
*     TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}
* };
*/
class Solution {
public:
int minDepth(TreeNode* root) {
if (!root) return 0;
int L = minDepth(root->left), R = minDepth(root->right);
return 1 + (min(L, R) ? min(L, R) : max(L, R));
}
};```

### 111. Minimum Depth of Binary Tree– Solution in Python

```# Definition for a binary tree node.
# class TreeNode(object):
#     def __init__(self, val=0, left=None, right=None):
#         self.val = val
#         self.left = left
#         self.right = right
class Solution(object):
def minDepth(self, root):
if not root: return 0
d = map(self.minDepth, (root.left, root.right))
return 1 + (min(d) or max(d))
```

Note: This problem 111. Minimum Depth of Binary Tree is generated by Leetcode but the solution is provided by CodingBroz. This tutorial is only for Educational and Learning purpose.