programming-examples/java/Data_Structures/Rational.java
2019-11-15 12:59:38 +01:00

92 lines
2.2 KiB
Java

import java.math.BigInteger;
public class Rational implements Comparable<Rational> {
public static final Rational ZERO = new Rational(0);
public static final Rational ONE = new Rational(1);
public static final Rational POSITIVE_INFINITY = new Rational(1, 0);
public static final Rational NEGATIVE_INFINITY = new Rational(-1, 0);
final BigInteger num;
final BigInteger den;
public Rational(BigInteger num, BigInteger den) {
BigInteger gcd = num.gcd(den);
BigInteger g = den.signum() > 0 ? gcd : den.signum() > 0 ? gcd.negate() : BigInteger.ONE;
this.num = num.divide(g);
this.den = den.divide(g);
}
public Rational(long num, long den) {
this(BigInteger.valueOf(num), BigInteger.valueOf(den));
}
public Rational(long num) {
this.num = BigInteger.valueOf(num);
this.den = BigInteger.ONE;
}
public Rational add(Rational r) {
return new Rational(num.multiply(r.den).add(r.num.multiply(den)), den.multiply(r.den));
}
public Rational sub(Rational r) {
return new Rational(num.multiply(r.den).subtract(r.num.multiply(den)), den.multiply(r.den));
}
public Rational mul(Rational r) {
return new Rational(num.multiply(r.num), den.multiply(r.den));
}
public Rational div(Rational r) {
return new Rational(num.multiply(r.den), den.multiply(r.num));
}
public Rational negate() {
return new Rational(num.negate(), den);
}
public Rational inverse() {
return new Rational(den, num);
}
public Rational abs() {
return new Rational(num.abs(), den);
}
public int signum() {
return num.signum();
}
public double doubleValue() {
return num.doubleValue() / den.doubleValue();
}
public long longValue() {
return num.longValue() / den.longValue();
}
public int compareTo(Rational other) {
return (num.multiply(other.den).compareTo(other.num.multiply(den)));
}
public boolean equals(Object obj) {
return num.equals(((Rational) obj).num) && den.equals(((Rational) obj).den);
}
public int hashCode() {
return num.hashCode() * 31 + den.hashCode();
}
public String toString() {
return num + "/" + den;
}
// Usage example
public static void main(String[] args) {
Rational a = new Rational(1, 3);
Rational b = new Rational(1, 6);
Rational c = new Rational(1, 2);
System.out.println(true == c.equals(a.add(b)));
}
}