Invert a binary tree.
4 / 2 7 / \ / 1 3 6 9
to
4 / 7 2 / \ / 9 6 3 1
反转二叉树,其实就是自顶向下递归翻转.代码如下:
# Definition for a binary tree node. # class TreeNode(object): # def __init__(self, x): # self.val = x # self.left = None # self.right = None class Solution(object): def invertTree(self, root): """ :type root: TreeNode :rtype: TreeNode """ if root: root.left, root.right = self.invertTree(root.right), self.invertTree(root.left) return root
原文：http://www.cnblogs.com/sherylwang/p/5661244.html