解题思路: 成对删除括号,直到序列长度不变,当序列为空时,合法 ''' # @param s string字符串 # @return bool布尔型 # def fun(s): t = [len(s),-1] while t[0] != t[1]: s = s.replace('()','') s = s.replace('[]','') s = s.replace('{}','') t.insert(0,len(s)) t.pop() return s class Solution: def isValid(self , s ): # write code here s2 = fun(s) if not s2: return True else: return False