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。