[leetcode]226. Invert Binary Tree翻转二叉树

佚名 6年前 (2019-05-16) 随笔 1364人围观抢沙发百度已收录

Invert a binary tree.

Example:

SRE实战互联网时代守护先锋，助力企业售后服务体系运筹帷幄！一键直达领取阿里云限量特价优惠。

Input:

     4
   /   \
  2     7
 / \   / \
1   3 6   9

Output:

     4
   /   \
  7     2
 / \   / \
9   6 3   1

code

 1 /**
 2  * Definition for a binary tree node.
 3  * public class TreeNode {
 4  *     int val;
 5  *     TreeNode left;
 6  *     TreeNode right;
 7  *     TreeNode(int x) { val = x; }
 8  * }
 9  */
10 class Solution {
11     public TreeNode invertTree(TreeNode root) {
12         if(null == root){
13             return null;
14         }
15         
16         TreeNode left = invertTree(root.left);
17         TreeNode right = invertTree(root.right);
18         root.left = right;
19         root.right = left;
20         
21         return root;
22     }
23 }