1190

class Solution {
public:
    string reverseParentheses(string s) {
        int sz = s.length();
        int pair[sz];
        string ans;
        int i, j;
        vector<int> stk;
        for(i=0; i<sz; i++){
            if(s[i] == '(')
                stk.push_back(i);
            else if(s[i] == ')'){
                j = stk.back();
                stk.pop_back();
                pair[i] = j;
                pair[j] = i;
            }
        }
        int d =1;
        for(i=0; i<sz; i+=d){
            if(s[i] == '(' || s[i] == ')'){
                i = pair[i];
                d = -d;
            }
            else{
                ans += s[i];
            }
        }
        return ans;
    }
};