32. Longest Valid Parentheses

https://leetcode.com/problems/longest-valid-parentheses/

Python

Stack

• Time: O(N)
• Space: O(N)

class Solution:
    def longestValidParentheses(self, s: str) -> int:
        max_length = 0

        stack = []
        stack.append((-1, ')'))

        for i, char in enumerate(s):
            if char == ')' and stack[-1][1] == '(':
                stack.pop()
                max_length = max(max_length, i-stack[-1][0])
            else:
                stack.append((i, char))

        return max_length