32. Longest Valid Parentheses *HARD*

Posted ArgenBarbie

tags:

篇首语:本文由小常识网(cha138.com)小编为大家整理,主要介绍了32. Longest Valid Parentheses *HARD*相关的知识,希望对你有一定的参考价值。

Given a string containing just the characters ‘(‘ and ‘)‘, find the length of the longest valid (well-formed) parentheses substring.

For "(()", the longest valid parentheses substring is "()", which has length = 2.

Another example is ")()())", where the longest valid parentheses substring is "()()", which has length = 4.

int longestValidParentheses(string s) {
    int maxLen = 0;
    int lastError = -1;
    vector<int> stack;
    for(int i=0; i<s.size(); i++)
    {
        if (s[i] == ()
            stack.push_back(i);
        else if (s[i] == ))
        {
            if (stack.size()>0 )
            {
                stack.pop_back();
                int len;
                if (stack.size()==0)
                    len = i - lastError;
                else
                    len = i - stack.back();
                if (len > maxLen)
                    maxLen = len;
            }
            else
                lastError = i;
        }
    }
    return maxLen;
}

 

以上是关于32. Longest Valid Parentheses *HARD*的主要内容,如果未能解决你的问题,请参考以下文章

32. Longest Valid Parentheses

32. Longest Valid Parentheses

32. Longest Valid Parentheses *HARD*

32. Longest Valid Parentheses

32. Longest Valid Parentheses

32. Longest Valid Parentheses