LeetCode 「简单」226.翻转二叉树
题目描述
给你一棵二叉树的根节点 root ，翻转这棵二叉树，并返回其根节点。
示例
输入：root = [4,2,7,1,3,6,9]
输出：[4,7,2,9,6,3,1]
输入：root = [2,1,3]
输出：[2,3,1]
输入：root = []
输出：[]
解答
Code
/**
* Definition for a binary tree node.
* function TreeNode(val, left, right) {
* this.val = (val===undefined ? 0 : val)
* this.left = (left===undefined ? null : left)
* this.right = (right===undefined ? null : right)
* }
*/
/**
* @param {TreeNode} root
* @return {TreeNode}
*/
var invertTree = function(root) {
if (!root) return root;
const temp = root.left;
root.left = root.right;
root.right = temp;
invertTree(root.left);
invertTree(root.right);
return root;
};