<p>Given two integers representing the <code>numerator</code> and <code>denominator</code> of a fraction, return <em>the fraction in string format</em>.</p>

<p>If the fractional part is repeating, enclose the repeating part in parentheses.</p>

<p>If multiple answers are possible, return <strong>any of them</strong>.</p>

<p>It is <strong>guaranteed</strong> that the length of the answer string is less than <code>10<sup>4</sup></code> for all the given inputs.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>

<pre>
<strong>Input:</strong> numerator = 1, denominator = 2
<strong>Output:</strong> &quot;0.5&quot;
</pre>

<p><strong class="example">Example 2:</strong></p>

<pre>
<strong>Input:</strong> numerator = 2, denominator = 1
<strong>Output:</strong> &quot;2&quot;
</pre>

<p><strong class="example">Example 3:</strong></p>

<pre>
<strong>Input:</strong> numerator = 4, denominator = 333
<strong>Output:</strong> &quot;0.(012)&quot;
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>-2<sup>31</sup> &lt;=&nbsp;numerator, denominator &lt;= 2<sup>31</sup> - 1</code></li>
	<li><code>denominator != 0</code></li>
</ul>

class Solution {
public:
    string fractionToDecimal(int numerator, int denominator) {
        if(numerator == 0) return "0";
        string answer;
        answer += ((numerator < 0) ^ (denominator < 0)) ? "-" : "";
        numerator = abs(numerator);
        denominator = abs(denominator);
        string integer = to_string(long(numerator / denominator));
        if(numerator % denominator == 0) return answer + integer;
        
        unordered_map<int, int> appearedIndex;
        long remainder = numerator % denominator;
        int decimal;
        string decimals = "";

        while(remainder != 0) {
            remainder *= 10;
            decimal = remainder / denominator;
            if(appearedIndex.find(remainder) != appearedIndex.end()) {
                decimals.insert(appearedIndex[remainder], "(");
                decimals += ')';
                break;
            }
            appearedIndex[remainder] = decimals.length();
            decimals += decimal + '0';
            remainder = remainder % denominator;
        }
        

        answer += integer + "." + decimals;
        return answer;
    }
};
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