LongestValidParentheses_OBF.cpp

class Solution {
public:
    int longestValidParentheses(string s) {
        int len_s = s.size();
        int counter = 0, maxLen = 0;
        
        for(int i = 0; i < len_s; i++){
            counter = 0;
            for(int j = i; j < len_s; j++){
                if(s[j] == '('){
                    counter ++;
                }
                else{
                    counter --;
                }
                
                if(counter < 0) break;
                
                if(counter == 0){
                    maxLen = max(maxLen, j - i + 1);
                }   
            }
        }
        return maxLen;
    }
};