对称二叉树

python 算法

解法一：

# -*- coding:utf-8 -*-
# class TreeNode:
#     def __init__(self, x):
#         self.val = x
#         self.left = None
#         self.right = None
class Solution:
    def isSymmetrical(self, pRoot):
        def is_same(p1, p2):
            if not (p1 or p2):
                return True
            elif p1 and p2 and p1.val == p2.val:
                return is_same(p1.left, p2.right) and is_same(p1.right, p2.left)
            return False
        if not pRoot:
            return True
        return is_same(pRoot.left, pRoot.right)