Scala如何定义有理数的排序

class Rational(n: Int, d: Int) {
  require(d != 0, "分母不能为零")

  private val gcdVal = gcd(n.abs, d.abs)
  val numerator: Int = n / gcdVal
  val denominator: Int = d / gcdVal

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

  def <(that: Rational): Boolean = {
    numerator * that.denominator < that.numerator * denominator
  }

  def >(that: Rational): Boolean = {
    numerator * that.denominator > that.numerator * denominator
  }

  override def toString: String = {
    numerator + "/" + denominator
  }
}

object RationalSortingExample {
  def main(args: Array[String]): Unit = {
    val rationalNumbers = Array(new Rational(1, 2), new Rational(3, 4), new Rational(1, 3))
    val sortedRationalNumbers = rationalNumbers.sortWith(_ < _)
    sortedRationalNumbers.foreach(println)
  }
}