void populateAfterDecimal(long num,long den,string &res){
    // key : remainder
    // value : position in res where the remainder occured for the first time
    unordered_map<long, long> m;
 
    string ans = "";
    while(num){
        // if num is not found in the map
        if(m.find(num) == m.end()){
            m[num] = res.size()-1;
            long q = num/den;
            long r = num%den;
 
            res+= to_string(q);
            num = r*10;
        } else {
            ans = res.substr(0,m[num]+1) + "(" + res.substr(m[num]+1,res.size()-m[num]) + ")";
            res = ans;
            break;
        }
 
    }
}
string fractionToDecimal(long numerator, long denominator) {
    if(numerator == 0) return "0";
 
    string res = "";
 
    // negative result
    if(numerator < 0 && denominator >0 || numerator > 0 && denominator < 0)
        res+="-";
    long num = abs(numerator);
    long den = abs(denominator);
 
    // before the decimal
    long q = num/den;
    long rem = num%den;
 
    res+=to_string(q);
 
    // decimal 
    if(rem == 0)
        return res;
    res += ".";
 
    // after the decimal processing
    populateAfterDecimal(rem*10,den,res);
    return res;
}