LeetCode翻转二叉树

翻转二叉树

LeetCode题目来源

1.1 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。

1.2 示例

2.1 解题

2.1.1 解题方法：使用递归进行计算

Java版解题

/**
 * 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 TreeNode invertTree(TreeNode root) {
        invertBinTree(root);
        return root;
    }

    void invertBinTree(TreeNode root){
        if(root == null){
            return;
        }

        TreeNode tn = new TreeNode();

        tn = root.left;
        root.left = root.right;
        root.right = tn;

        invertBinTree(root.left);
        invertBinTree(root.right);

        return;
    }
}

解题结果