题目链接：二叉树的镜像

import java.util.*;/** public class TreeNode {*   int val = 0;*   TreeNode left = null;*   TreeNode right = null;*   public TreeNode(int val) {*     this.val = val;*   }* }*/public class Solution {/*** 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可** * @param pRoot TreeNode类 * @return TreeNode类*/public TreeNode Mirror (TreeNode root) {if(root == null) return null;TreeNode t = root.left;root.left = root.right;root.right = t;Mirror(root.left);Mirror(root.right);return root;}
}