# Leetcode 166
###### tags: `LeetCode`
**Solution**
Runtime: 3 ms, faster than 9.01%
Memory Usage: 35.5 MB, less than 90.48%

public static String fractionToDecimal(int numerator, int denominator) {
long numeratorL = numerator;
long denominatorL = denominator;
StringBuilder sb = new StringBuilder();
long remainder = numeratorL % denominatorL;
if(numerator < 0 && denominator > 0 || numerator > 0 && denominator < 0 ) {
sb.append("-");
}
numeratorL = Math.abs(numeratorL);
denominatorL = Math.abs(denominatorL);
remainder = numeratorL % denominatorL;
sb.append(numeratorL / denominatorL);
if(remainder == 0) return sb.toString();
sb.append(".");
List<Long> list = new ArrayList<Long>();
list.add(remainder);
String temp = "";
long t = System.currentTimeMillis();
while(true) {
long idx = (remainder * 10) % denominatorL;
if(list.indexOf(idx) != -1) {
if(list.indexOf(idx) == 0) {
temp += (remainder * 10) / denominatorL;
sb.append("(");
sb.append(temp);
sb.append(")");
}else if(idx == 0) {
sb.append(temp);
}else {
temp += (remainder * 10) / denominatorL;
sb.append(temp.substring(0,list.indexOf(idx)));
sb.append("(");
sb.append(temp.substring(list.indexOf(idx)));
sb.append(")");
}
break;
}
temp += (remainder * 10) / denominatorL;
remainder = idx;
list.add(idx);
}
System.out.println("t:"+(System.currentTimeMillis()-t));
return sb.toString();
}