Fraction to Recurring Decimal LeetCode solution in C++

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class Solution {
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 public:
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  string fractionToDecimal(int numerator, int denominator) {
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    unordered_map<int, int> umap;
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    string result = "";
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    if ((double)numerator / (double)denominator < 0) result.push_back('-');
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    long long l_numerator = numerator > 0 ? numerator : -(long long)numerator;
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    long long l_denominator = denominator > 0 ? denominator : -(long long)denominator;
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    long long quotient = l_numerator / l_denominator;
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    long long remainder = l_numerator % l_denominator;
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    result.append(to_string(quotient));
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    if (remainder == 0) return result;
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    result.push_back('.');
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    int position = result.size();
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    umap[remainder] = position++;
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    while (remainder != 0) {
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      l_numerator = remainder * 10;
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      quotient = l_numerator / l_denominator;
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      remainder = l_numerator % l_denominator;
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      char digit = '0' + quotient;
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      result.push_back(digit);
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      if (umap.find(remainder) != umap.end()) {
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        result.insert(umap[remainder], 1, '(');
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        result.push_back(')');
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        return result;
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      }
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      umap[remainder] = position++;
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    }
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    return result;
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  }
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};