#-*- coding: UTF-8 -*-
# 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):
resultBool=True
def isSymmetric(self, root):
"""
:type root: TreeNode
:rtype: bool
"""
if root==None:return True
if root.left==root.right==None:return True
elif root.left==None or root.right==None:return False
if root.left.val==root.right.val:
self.dnf(root.left,root.right)
return self.resultBool
else:
return False
def dnf(self,root1,root2):
if root1==None and root2==None:return
elif root1==None or root2==None :self.resultBool=False;return
if root1.val!=root2.val:
self.resultBool=False
self.dnf(root1.left,root2.right)
self.dnf(root1.right,root2.left)
