class Solution {

public:

    string fractionToDecimal(int numerator, int denominator) {

        if((numerator==INT_MIN||numerator==INT_MAX)&&(denominator==||denominator==-)){

            if(numerator==INT_MIN){

                return denominator==?"-2147483648":"";

            }

            if(numerator==INT_MAX){

                return denominator==-?"-2147483647":"";

            }

        }

        if(denominator==) return "";

        string res;

        int sign=numerator^denominator;

        if(numerator==) sign=;

        long num=labs(numerator),den=labs(denominator),ans=,r=;

        for(int i=;i>=;i--){

            if((num>>i)>=den){

                ans+=<<i;

                num-=den<<i;

            }

        }

        r=num;

        if(ans==) res+="";

        while(ans!=){

            res+=ans%+'';

            ans=ans/;

        }

        if(sign<) res+="-";

        reverse(res.begin(),res.end());

        if(r!=)

            res+=".";

        int rst=,flag=;

        unordered_map<int,int>m;

        string right;

        int i=;

        //此处分数不会是无线不循环小数，因此只需要判断是否除尽和是否循环两个break条件就可以了；

        while(r!=){

            r*=;

            if(m.count(r)) {flag=;break;}

            m[r]=i;

            if(r>den){

                rst=r/den;

                r=r-rst*den;

                right.push_back(''+rst);

            }else{

                right+="";

            }

            i++;

        }

        if(flag==){

            res=res+right.substr(,m[r])+"("+right.substr(m[r])+")";

        }else{

            res+=right;

        }

        return res;

    }

};