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)".
public String fractionToDecimal(int numerator, int denominator) {
String sign = "";
if (Math.signum(numerator) * Math.signum(denominator) < 0) {
sign = "-";
}
long n = Math.abs(numerator);
long d = Math.abs(denominator);
String intPart = Math.abs(n / d) "";
// 如果整除，直接返回结果
if (n % d == 0) {
return sign intPart;
}
// 计算小数部分
n %= d;
n *= 10;
StringBuilder sb = new StringBuilder();
Map<Long, Integer> mod = new HashMap<Long, Integer>();
for (int i = 0; n != 0; i ) {
long q = n / d;
Integer start = mod.get(n / 10);
if (start != null) {
sb.insert(start, "(");
sb.append(")");
break;
}
sb.append(Math.abs(q));
mod.put(n / 10, i);
n %= d;
n *= 10;
}
String fractionalPart = sb.toString();
return sign intPart "." fractionalPart;
}
