力扣--LCR 144.翻转二叉树

题目

给定一棵二叉树的根节点 root，请左右翻转这棵二叉树，并返回其根节点。

示例 1：

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 TreeNode flipTree(TreeNode root) {
  if(root == null || root.left == null&& root.right == null){
  return root;
  }
  TreeNode left = flipTree(root.left);
  TreeNode right = flipTree(root.right);
  root.left = right;
  root.right = left;
  return root;
  }
  }
  时间复杂度：O(n)
  空间：树的高度。