目录
226. 翻转二叉树
思路
代码
本地代码测试
不管前方的路有多苦
只要走的方向正确
不管多么崎岖不平
都比站在原地更接近幸福
—— 24.10.21
226. 翻转二叉树
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 1：
输入：root = [4,2,7,1,3,6,9] 输出：[4,7,2,9,6,3,1]示例 2：
输入：root = [2,1,3] 输出：[2,3,1]示例 3：
输入：root = [] 输出：[]
思路
代码
/*** Definition for a binary tree node.* public class TreeNode {* int val;* TreeNode left;* TreeNode right;* TreeNode() {}* TreeNode(int val) { this.val = val; }* TreeNode(int val, TreeNode left, TreeNode right) {* this.val = val;* this.left = left;* this.right = right;* }* }*/
class Solution {public static TreeNode invertTree(TreeNode root) {fn(root);return root;}private static void fn(TreeNode root) {if (root == null) {return;}TreeNode temp = root.left;root.left = root.right;root.right = temp;fn(root.left);fn(root.right);}
}
本地代码测试
public class LeetCode226ReverseBinaryTree {public static TreeNode invertTree(TreeNode root) {fn(root);return root;}private static void fn(TreeNode root) {if (root == null) {return;}TreeNode temp = root.left;root.left = root.right;root.right = temp;fn(root.left);fn(root.right);}private static void Print(TreeNode root, String indent) {if (root == null) {return;}System.out.println(indent + root.value);Print(root.left, indent + " |-- ");Print(root.right, indent + " |-- ");}public static void main(String[] args) {TreeNode root = new TreeNode(1,new TreeNode(2,new TreeNode(4),new TreeNode(5,new TreeNode(7), null)),new TreeNode(3,null,new TreeNode(6)));TreeNode invertedRoot = invertTree(root);Print(invertedRoot,"");}
}
