2021.10.3打卡

class Solution {
public:
    string fractionToDecimal(int numerator, int denominator) {
        long numeratorLong = numerator, denominatorLong = denominator;
        if(numeratorLong % denominatorLong == 0)
            return to_string(numeratorLong/denominatorLong);
        
        string ans;
        if(numeratorLong<0 ^ denominatorLong<0){
            ans +="-";
            numeratorLong = abs(numeratorLong);
            denominatorLong = abs(denominatorLong);
        }
        
        ans += to_string(numeratorLong / denominatorLong)+ ".";
        string fractionPart;
        long remind=numeratorLong % denominatorLong;
        unordered_map mp;
        int index=0;
        while(remind != 0 && !mp.count(remind))
        {
            mp[remind] = index;
            fractionPart += to_string(remind * 10 /denominatorLong);
            remind = remind * 10 % denominatorLong;
            index++;
        }
        if(remind!=0)
            fractionPart = fractionPart.substr(0,mp[remind])+"("+fractionPart.substr(mp[remind])+")";
        
        ans += fractionPart;

        return ans;
    }
};