Project Euler: Problem 38

Euler0038.scala

package euler.zerosum

import euler.zerosum.Number._

object Euler0038 {

  private val nums = from(1).take(9999)
  private val digits = (1 to 9).toList
  private val nineDigitNums: Set[String] = digits.permutations.map(_.mkString).toSet

  def main(args: Array[String]) {

    println(nums
            .par
            .map(n => digits.scanLeft("")((a, b) => a + b * n).filter(nineDigitNums.contains(_)).headOption)
            .collect {case Some(x) => x}
            .max
    )
  }
}