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@felipeska
Created February 15, 2023 03:01
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package rationals
import java.math.BigInteger
data class Rational(val n: BigInteger, val d: BigInteger): Comparable<Rational> {
init { require(d != BigInteger.ZERO ) {"Zero is not allowed in the denominator"} }
override fun toString(): String {
if (this.d == BigInteger.ONE) return "${this.n}"
return "$n/$d"
}
override fun compareTo(other: Rational): Int {
return n.times(other.d).compareTo(other.n.times(d))
}
}
fun String.toRational(): Rational = if (this.contains("/")) {
val split = this.split("/")
val n = split[0].toBigInteger()
val d = split[1].toBigInteger()
// normalize
val g = n.gcd(d)
val num = n / g
val den = d / g
if(den < BigInteger.ZERO)
Rational(-num, den.abs())
else
Rational(num, den)
} else {
Rational(this.toBigInteger(), BigInteger.ONE)
}
infix fun Int.divBy(d: Int): Rational = Rational(this.toBigInteger(), d.toBigInteger()).toString().toRational()
infix fun Long.divBy(d: Long): Rational = Rational(this.toBigInteger(), d.toBigInteger()).toString().toRational()
infix fun BigInteger.divBy(d: BigInteger): Rational = Rational(this, d).toString().toRational()
operator fun Rational.unaryMinus(): Rational = Rational(-this.n, this.d)
operator fun Rational.plus(other: Rational): Rational {
return if (this.d == other.d) {
val n = this.n + other.n
val d = this.d
Rational(n, d).toString().toRational()
} else {
val d = this.d * other.d
val na = this.n * other.d
val nb = other.n * this.d
val n = na + nb
Rational(n, d).toString().toRational()
}
}
operator fun Rational.minus(other: Rational): Rational {
return if (this.d == other.d) {
val n = this.n + other.n
val d = this.d
Rational(n, d).toString().toRational()
} else {
val d = this.d * other.d
val na = this.n * other.d
val nb = other.n * this.d
val n = na - nb
Rational(n, d).toString().toRational()
}
}
operator fun Rational.times(other: Rational): Rational =
Rational(this.n * other.n, this.d * other.d).toString().toRational()
operator fun Rational.div(other: Rational): Rational {
val n = this.n * other.d
val d = this.d * other.n
return Rational(n, d).toString().toRational()
}
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