A more general approach to resolve verbal arithmetic using scala API, completely based on the talk by Filippo Vitale => https://youtu.be/sot44l8zKuo

VerbalArithmetic.scala

/**
  * Created by simone.picciani on 21/12/2016.
  */
object ScalaAPI {


  def main(args: Array[String]): Unit = {
    val initTime = System.currentTimeMillis

    //    val phrase = "send more money"
    val phrase = "leia luke han rebel"
    val phraseNoSpaces = phrase.replace(" ", "")
    val phraseList = phrase split " " toList

    val question = phraseList init
    val initials = phraseList map (_.head)
    val answer = phraseList last


    val maps = for {
      combination <- (0 to 9).combinations(phraseNoSpaces.distinct.length)
      permutation <- combination.permutations
    } yield (phraseNoSpaces.distinct zip permutation).toMap

    val reducer = (str: String, m: Map[Char, Int]) => str map m reduce (_ * 10 + _)

    val solutions = {
      val result = for {
        m <- maps if initials forall (m(_) != 0)
        first = question.map(reducer(_, m))
        last = reducer(answer, m)
        if first.sum == last
      } yield (first, last)
      result
    }
    println(s"result is ${solutions.next()}")


    val elapsedTime = System.currentTimeMillis - initTime
    println(s"Total Duration of scalaAPI-> $elapsedTime ms")


  }
}