题解 | #二叉树的最小深度#

import java.util.*;

/*
 * public class TreeNode {
 *   int val = 0;
 *   TreeNode left = null;
 *   TreeNode right = null;
 * }
 */

public class Solution {
    /**
     * 
     * @param root TreeNode类 
     * @return int整型
     */
    public int run (TreeNode root) {
        // write code here
       if(root==null){
             return 0;
         }
        int left  = run(root.left);
        int right  = run(root.right);
        if(left*right >0){
            return (left>right?right:left)+1;
        }else{
            return (left>right?left:right)+1;
        }
    }
}