Fraction to Recurring Decimal

Given two integers representing the numerator and denominator of a fraction, return the fraction in string format.

If the fractional part is repeating, enclose the repeating part in parentheses.

For example,

• Given numerator = 1, denominator = 2, return "0.5".
• Given numerator = 2, denominator = 1, return "2".
• Given numerator = 2, denominator = 3, return "0.(6)".

class Solution {
public:
    string getFraction(long long numerator, long long denominator) {
     
        string fraction = ".";
        numerator *= 10;
        map<long long, int> mp;
        int pos = 1;

        while (numerator != 0) {
            if (mp.find(numerator) != mp.end()) {
                fraction.insert(mp[numerator], 1, '(');
                fraction.push_back(')');
                return fraction;
            } else {
                mp[numerator] = pos;
            }
            fraction += to_string(numerator / denominator);      
            numerator = 10 * (numerator % denominator);
            pos++;
        }
        return fraction;
     
    }
    string fractionToDecimal(int num, int den) {
        string ans; bool sign = false;
        if (den == 0 || num == 0) {
            return "0";
        }
        if ((den < 0 && num < 0) ||
            (den > 0 && num > 0)) {
            sign = true;
        }
        long long numerator = abs((long long) num);
        long long denominator = abs((long long) den);
     
        ans += to_string(numerator / denominator);
        if (numerator % denominator != 0) {
            ans += getFraction(numerator % denominator, denominator);
        }
        return (sign == false ? "-" + ans : ans);
    }
};


========

string fractionToDecimal(int numerator, int denominator) {
        int s1 = numerator >= 0 ? 1 : -1;
        int s2 = denominator >= 0 ? 1 : -1;
        long long num = abs( (long long)numerator );
        long long den = abs( (long long)denominator );
        long long out = num / den;
        long long rem = num % den;
        unordered_map<long long, int> m;
        string res = to_string(out);
        if (s1 * s2 == -1 && (out > 0 || rem > 0)) res = "-" + res;
        if (rem == 0) return res;
        res += ".";
        string s = "";
        int pos = 0;
        while (rem != 0) {
            if (m.find(rem) != m.end()) {
                s.insert(m[rem], "(");
                s += ")";
                return res + s;
            }
            m[rem] = pos;
            s += to_string((rem * 10) / den);
            rem = (rem * 10) % den;
            ++pos;
        }
        return res + s;
    }

==========

class Solution {
public:
    string fractionToDecimal(int num, int denom) {
        int sign_a = (num < 0 ? -1 : 1);
        int sign_b = (denom < 0 ? -1 : 1);
        
        string ans;
        if (denom == 0 || num == 0) {
            return "0";
        }
        
        long numerator = labs(num);
        long denominator = labs(denom);
        
        if (sign_a * sign_b == -1) {
            ans += "-";
        }
        long remaining = numerator % denominator;
        ans += to_string(numerator/denominator);
        if (remaining == 0) {
            return ans;
        } else {
            ans += ".";
        }
        // Prepare the fraction.
        map<long, long> mp;
        while (1) {
            if (mp.count(remaining) != 0) {
                string tmp = ans.substr(mp[remaining]);   // 6
                string pre = ans.substr(0, mp[remaining]); // 0.
                return pre + "(" + tmp + ")";
            }
            if (remaining == 0) {
                return ans;
            }
            mp[remaining] = ans.size();   // mp[4] = 2
            int count = 0;
            while (remaining < denominator) {
                remaining *= 10;
                count++;
            }
            while (count > 1) {
                ans += "0";
                count--;
            }
            ans += to_string(remaining/denominator);  // 0.6
            remaining = remaining % denominator;
        }
        return ans;
    }
};