Minimum Depth of Binary Tree

1. Title

2. Http address

https://leetcode.com/problems/minimum-depth-of-binary-tree/

3. The question

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.

4 My code(AC)

 1     public static int DFS(TreeNode root, int depth,int min){
 2         
 3         if( root == null)
 4             return Math.min(depth, min);
 5         if( root.left == null && root.right == null)
 6         {
 7             return Math.min(depth + 1, min);
 8         }
 9         
10         int min_left = Integer.MAX_VALUE;
11         if( root.left != null)
12                 min_left = DFS(root.left, depth + 1, min);
13         int min_right = Integer.MAX_VALUE;
14         if( root.right != null)
15             min_right = DFS(root.right, depth + 1, min);
16         
17         return Math.min(min_left, min_right);
18     }
19     
20     // Accepted
21       public static int minDepth(TreeNode root) {
22          
23           return DFS(root,0,Integer.MAX_VALUE);
24         }