Python ：二叉树的镜像

牛客网上的剑指 offer的在线编程：

题目描述:

操作给定的二叉树，将其变换为源二叉树的镜像。

# -*- coding:utf-8 -*-# class TreeNode:#     def __init__(self, x):#         self.val = x#         self.left = None#         self.right = Noneclass Solution:    # 返回镜像树的根节点    def Mirror(self, root):        if root is None:            return        if not root.left is None:            self.Mirror(root.left)        if not root.right is None:            self.Mirror(root.right)        temp = root.left        root.left = root.right        root.right = temp        return root