🌵32. Longest Valid Parentheses
https://leetcode.com/problems/longest-valid-parentheses/
js
/**
* @param {string} s
* @return {number}
*/
var longestValidParentheses = function(s) {
var result = 0
var stack = []
for (let i = 0; i < s.length; i++) {
let ch = s[i]
if (ch === ')' && stack.length && s[stack[stack.length - 1]] === '(') {
stack.pop()
if (stack.length) {
result = Math.max(result, i - stack[stack.length - 1])
} else {
result = i + 1
}
} else {
stack.push(i)
}
}
return result
}py
class Solution(object):
def longestValidParentheses(self, s):
"""
:type s: str
:rtype: int
"""
result, stack = 0, []
for i, c in enumerate(s):
if c == ')' and len(stack) > 0 and s[stack[-1]] == '(':
stack.pop()
if len(stack) > 0:
result = max(result, i - stack[-1])
else:
result = i + 1
else:
stack.append(i)
return result