RosettaCodeData/Task/Arithmetic-Rational/Scala/arithmetic-rational-1.scala

45 lines
1.3 KiB
Scala

class Rational(n: Long, d:Long) extends Ordered[Rational]
{
require(d!=0)
private val g:Long = gcd(n, d)
val numerator:Long = n/g
val denominator:Long = d/g
def this(n:Long)=this(n,1)
def +(that:Rational):Rational=new Rational(
numerator*that.denominator + that.numerator*denominator,
denominator*that.denominator)
def -(that:Rational):Rational=new Rational(
numerator*that.denominator - that.numerator*denominator,
denominator*that.denominator)
def *(that:Rational):Rational=
new Rational(numerator*that.numerator, denominator*that.denominator)
def /(that:Rational):Rational=
new Rational(numerator*that.denominator, that.numerator*denominator)
def unary_~ :Rational=new Rational(denominator, numerator)
def unary_- :Rational=new Rational(-numerator, denominator)
def abs :Rational=new Rational(Math.abs(numerator), Math.abs(denominator))
override def compare(that:Rational):Int=
(this.numerator*that.denominator-that.numerator*this.denominator).toInt
override def toString()=numerator+"/"+denominator
private def gcd(x:Long, y:Long):Long=
if(y==0) x else gcd(y, x%y)
}
object Rational
{
def apply(n: Long, d:Long)=new Rational(n,d)
def apply(n:Long)=new Rational(n)
implicit def longToRational(i:Long)=new Rational(i)
}