牛客網上的劍指 offer的在線編程:
題目描述
class TreeNode:
def __init__(self, x):
self.val = x
self.left = None
self.right = None
class Solution:
def isSymmetrical(self, pRoot):
# write code here
def is_same(p1, p2):
if not p1 and not p2:
return True
if (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
if not pRoot.left and pRoot.right:
return False
if pRoot.left and not pRoot.right:
return False
return is_same(pRoot.left, pRoot.right)