Rational v1

gistfile1.scala

class Rational(n: Int, d: Int) {

    require(d!= 0)

    private val g = gcd(n.abs, d.abs)

    val numer = n / g
    val denom = d / g

    def this(n: Int) = this(n, 1)

    def + (that: Rational): Rational = {
        new Rational(
            numer * that.denom + that.numer * denom,
            denom * that.denom
        )
    }

    def + (i: Int): Rational = {
        new Rational(numer + i * denom, denom)
    }

    def - (that: Rational) = {
        new Rational(
            numer * that.denom - that.numer * denom,
            denom * that.denom
        )
    }

    def - (i: Int): Rational = {
        new Rational(numer - i * denom, denom)
    }

    def * (that: Rational): Rational = {
        new Rational(
            numer * that.numer,
            denom * that.denom
        )
    }

    def * (i: Int):Rational = {
        new Rational(numer * i, denom)
    }

    def / (that: Rational):Rational = {
        new Rational(
            numer * that.denom,
            denom * that.numer
        )
    }

    def / (i: Int):Rational = {
        new Rational(numer, denom * i)
    }

    override def toString = numer + "/" + denom

    private def gcd(a: Int, b: Int): Int = {
        if (b == 0) a else gcd(b, a % b)
    }
}