今天又看了一遍，python的动规逻辑是错误的。我认为正确的写法如下： class Solution: def longestValidParentheses(self , s: str) -> int: # write code here len1 = len(s) if len1 <=1: return 0 dp = [0]*(len1+1) if s[0]=='(' and s[1]==')': dp[1] =2 for i in range(2,len1): if(s[i]==')'): if s[i-1]=='(': dp[i] = dp[i-2]+2 elif s[i-dp[i-1]-1]=='(': if i - dp[i - 1]-2> 0: dp[i] = dp[i - dp[i - 1] - 2] + dp[i - 1] + 2 else: dp[i] = dp[i - 1] + 2 return max(dp)