ScalaMul.scala

import scala.actors.Futures._

object ScalaMul {
  val cores = Runtime.getRuntime().availableProcessors()
  val sets = (1 to cores).map(_ to 200000 by cores)
  val jobs = sets.map(set => future(set.foldLeft(BigInt(1))(_ * _)))
  val mult = awaitAll(3600000, jobs:_*).foldLeft(BigInt(1))(_ * _.get.asInstanceOf[BigInt])
  def main(args: Array[String]) = println(mult)
}

// object ScalaMul {
//   def mul(range: NumericRange[BigInt]): BigInt = {
//     def half(f: Int => NumericRange[T]) = future(mul(f(range.length / 2)))
//     if (range.length < 50000)  range.foldLeft(BigInt(1))(_ * _)
//     else awaitAll(3600 * 1000, half(range.take), half(range.drop).foldLeft(BigInt(1))(_ * _.get.asInstanceOf[BigInt])
//   }
//   def main(args: Array[String]) = println(mul((BigInt(1) to BigInt(200000))))
// }

// object ScalaMul {
//   def mul(r: Range): BigInt = { var i = r.start; var sum: BigInt = 1; while (i <= r.end) { i += r.step; sum *= i }; return sum }
//   val cores = Runtime.getRuntime().availableProcessors()
//   val jobs = (1 to cores).map(_ to 1000000 by cores).map(range => future(mul(range)))
//   def main(args: Array[String]) = println(awaitAll(1000000, jobs: _*).map(_.get.asInstanceOf[BigInt]).sum)
// }