请完成一个函数,输入一个二叉树,该函数输出它的镜像。
例如输入:
4
/ \
2 7
/ \ / \
1 3 6 9
镜像输出:
4
/ \
7 2
/ \ / \
9 6 3 1
输入:root = [4,2,7,1,3,6,9]
输出:[4,7,2,9,6,3,1]
# Definition for a binary tree node.
# class TreeNode:
# def __init__(self, x):
# self.val = x
# self.left = None
# self.right = None
class Solution:
def mirrorTree(self, root: TreeNode) -> TreeNode:
if not root:
return None
right = self.mirrorTree(root.right)
left = self.mirrorTree(root.left)
root.right = left
root.left = right
return root