111. 二叉树的最小深度

/**
 * Definition for a binary tree node.
 * public class TreeNode {
 *     int val;
 *     TreeNode left;
 *     TreeNode right;
 *     TreeNode(int x) { val = x; }
 * }
 */
class Solution {
    public int minDepth(TreeNode root) {
        if(root==null)
            return 0;
        if(root.left==null)
            return minDepth(root.right)+1;
        if(root.right==null)
            return minDepth(root.left)+1;
        return Math.min(minDepth(root.left),minDepth(root.right))+1;
        
    }
}

题目链接：

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

解题思路：