ChargingChaos.scala

object ChargingChaos extends App {

  def minMove(inputs: Seq[String]): Option[Int] = {
    val (chars, lengths) = inputs.map(runLength(_).unzip).unzip
    if ((Set.empty[List[Char]] /: chars)(_ + _).size > 1) None 
    else Some {
      val diffs = (List.fill(lengths.head.size)(List.empty[Int]) /: lengths) {
        (acc, v) =>
          (acc zip v).map {
            case (acc, x) => x :: acc
          }
      } map (_.toVector.sorted)
      (for (diff <- diffs) yield {
        val median = diff(diff.size / 2)
        (for {
          x <- diff
        } yield math.abs(x - median)).sum
      }).sum
    } 
  }

  def runLength(s: String): List[(Char, Int)] = {
    (((s.head, 1) :: Nil) /: s.tail) {
      case ((c, n) :: tail, char) if c == char =>
        (c, n + 1) :: tail
      case (acc, char) =>
        (char, 1) :: acc
    }
  }.reverse

  def process(iter: Iterator[String])(out: String => Unit) =
    for (i <- 1 to iter.next().toInt) {
      val n = iter.next().toInt
      val input = Seq.fill(n)(iter.next())
      out(s"Case #$i: ${minMove(input) getOrElse "Fegla Won"}")
    }

  import java.io._
  val out = new PrintStream(new File("a.out"))
  try {
    process(io.Source.fromFile("A-large-practice.in").getLines) { s: String =>
      out.println(s)
    }
  } finally {
    out.flush; out.close
  }

}