| |
| public final class Fraction implements Comparable<Fraction> { |
| private final long num; |
| private final long den; |
|
|
| public Fraction(long num, long den) { |
| if (den == 0) { |
| throw new ArithmeticException("denominator is zero"); |
| } |
| if (den < 0) { |
| num = -num; |
| den = -den; |
| } |
| long g = gcd(Math.abs(num), den); |
| this.num = num / g; |
| this.den = den / g; |
| } |
|
|
| static long gcd(long a, long b) { |
| while (b != 0) { |
| long t = a % b; |
| a = b; |
| b = t; |
| } |
| return a == 0 ? 1 : a; |
| } |
|
|
| public long numerator() { return num; } |
|
|
| public long denominator() { return den; } |
|
|
| public Fraction add(Fraction o) { |
| return new Fraction(num * o.den + o.num * den, den * o.den); |
| } |
|
|
| public Fraction subtract(Fraction o) { |
| return new Fraction(num * o.den - o.num * den, den * o.den); |
| } |
|
|
| public Fraction multiply(Fraction o) { |
| return new Fraction(num * o.num, den * o.den); |
| } |
|
|
| public Fraction divide(Fraction o) { |
| if (o.num == 0) { |
| throw new ArithmeticException("division by zero"); |
| } |
| return new Fraction(num * o.den, den * o.num); |
| } |
|
|
| public double toDouble() { |
| return (double) num / den; |
| } |
|
|
| @Override |
| public int compareTo(Fraction o) { |
| return Long.compare(num * o.den, o.num * den); |
| } |
|
|
| @Override |
| public boolean equals(Object other) { |
| if (this == other) return true; |
| if (!(other instanceof Fraction)) return false; |
| Fraction f = (Fraction) other; |
| return num == f.num && den == f.den; |
| } |
|
|
| @Override |
| public int hashCode() { |
| return Long.hashCode(num) * 31 + Long.hashCode(den); |
| } |
|
|
| @Override |
| public String toString() { |
| return den == 1 ? Long.toString(num) : num + "/" + den; |
| } |
| } |
|
|
