Golang | Leetcode Golang题解之第32题最长有效括号

题目：

题解：

func longestValidParentheses(s string) int {
    left, right, maxLength := 0, 0, 0
    for i := 0; i < len(s); i++ {
        if s[i] == '(' {
            left++
        } else {
            right++
        }
        if left == right {
            maxLength = max(maxLength, 2 * right)
        } else if right > left {
            left, right = 0, 0
        }
    }
    left, right = 0, 0
    for i := len(s) - 1; i >= 0; i-- {
        if s[i] == '(' {
            left++
        } else {
            right++
        }
        if left == right {
            maxLength = max(maxLength, 2 * left)
        } else if left > right {
            left, right = 0, 0
        }
    }
    return maxLength
}

func max(x, y int) int {
    if x > y {
        return x
    }
    return y
}