括号序列的python实现
#
# 代码中的类名、方法名、参数名已经指定,请勿修改,直接返回方法规定的值即可
#
#
# @param s string字符串
# @return bool布尔型
#
class Solution:
def isValid(self , s: str) -> bool:
# write code here
dic = {'(':')', '{': '}', '[':']', '?':'?'}
mystack = ['?']
for c in s:
if c in dic: mystack.append(c)
elif dic[mystack.pop()]!=c: return False
return len(mystack)==1