LeetCode - Minimum Depth of Binary Tree

/**
* Definition for binary tree
* public class TreeNode {
*     int val;
*     TreeNode left;
*     TreeNode right;
*     TreeNode(int x) { val = x; }
* }
*/
public class Solution {
public int minDepth(TreeNode root) {
if(root == null)
return 0;
int l = minDepth(root.left);
int r = minDepth(root.right);
if(l==0)
return r+1;
else if(r==0)
return l+1;
else
return r<l? r+1:l+1;
}

}

/**
* Definition for binary tree
* public class TreeNode {
*     int val;
*     TreeNode left;
*     TreeNode right;
*     TreeNode(int x) { val = x; }
* }
*/
public class Solution {
public static int MIN = 9999999;
public static int minDepth(TreeNode root) {
if(root == null)
return 0;
dfs(root, MIN, 1);
return MIN;
}
public static void dfs(TreeNode root, int min, int cnt) {
if(root == null) return ;
if(root.left==null && root.right==null) {
if(min > cnt) {
min = cnt;
MIN = min;
}
return ;
}
dfs(root.left, min, cnt+1);
dfs(root.right, min, cnt+1);
return ;
}

}