ReadPhoneNumber.scala

package test

import scala.collection.mutable
import scala.io.Source
import java.io.{ File, PrintStream }


object ReadPhoneNumber {
  def numberMap = Map((1, "one"), (2, "two"), (3, "three"), 
      (4, "four"), (5, "five"), (6, "six"), (7, "seven"), (8, "eight"), (9, "nine"))
  def freqMap = Map((1, ""), (2, "double "), (3, "triple "), (4, "quadruple "),
      (5, "quintuple "),(6, "sextuple "),(7, "septuple "),(8, "octuple "),(9, "nonuple "), (10, "decuple "))

  def readPhoneNumber(number: String, lengths: List[Int]): String = {
    //val indexs = lengths.foldLeft(0){ (x, y) => x + y }
    var prevSum = 0
    val indexes = for (length <- lengths) yield {
      val prevPrevSum = prevSum
      prevSum += length
      (prevPrevSum, prevSum)
    }

    val segments = indexes.map {
      case (i, j) =>
        number.substring(i, j)
    }
    segments.foreach { readSegment }
    ""
  }

  def readSegment(segment: String): String = {
    def readSegmentInner(segment: String, acc: List[(Int, Char)]): List[(Int, Char)] = {
      if (segment.isEmpty) acc
      else {
        val seg = segment.charAt(0)
        val segment1 = segment.substring(1)
        acc match {
          case Nil => readSegmentInner(segment1, List((1, seg)))
          case head :: tail =>
            if (head._2 == seg) readSegmentInner(segment1, (head._1 + 1, head._2) :: tail)
            else readSegmentInner(segment1, List((1, seg)) ::: acc)
        }
      }
    }

    val countCharPair: List[(Int, Char)] = readSegmentInner(segment, List()).reverse
    
    val reads: List[String] = for((count, ch) <- countCharPair ) yield {
      count match {
        case x if x > 10 => for( i<- 1 to count) yield { numberMap(ch.toInt) }.mkString(" ")
        case _ => (freqMap(count) + numberMap(ch.toInt)).toString
      }
    }
    
    reads.mkString(" ")
  }

  def process(iter: Iterator[String])(pr: String => Unit) {

    for (i <- 1 to iter.next().toInt) yield {
      val Array(a, b) = iter.next().toString split ' '
      val lengths = b.split('-').map(_.toInt)

      pr(s"Case #$i: ${readPhoneNumber(a, lengths.toList)}")
    }
  }

  def main(args: Array[String]) {
    val in = Source.fromFile(new File("test.in"))
    val out = new PrintStream(new File("test.out"))
    try {
      process(in.getLines) { s: String => println(s) }
    } finally {
      out.flush; out.close
    }
  }
}