ReverseTest.scala

object ReverseTest {

  def solve(input: Seq[String]): String = {
    def solve(left: Seq[String], right: Seq[String], result: Seq[String]): Seq[String] = {
      (left.isEmpty, right.isEmpty) match {
		  case (false, true) => solve(left.init, Nil, result :+ left.last)
		  case (true, false) => solve(Nil, right.tail, right.head +: result)
		  case (false, false) => solve(left.init, right.tail, right.head +: result :+ left.last)
		  case _ => result
		}
    }
    val (left, right) = input splitAt (input.size / 2)
    solve(left, right, Seq()).mkString(" ");
  }
  
  def main(args: Array[String]) {
    run()
  }

  def run() {
    val writer = new java.io.PrintWriter("b-large.out")
    try {
      process(io.Source.fromFile("B-large-practice.in").getLines)(writer.println)
    } finally {
      writer.flush()
      writer.close()
    }
  }

  def process(lineIn: Iterator[String])(lineOut: String => Unit) = {
    for (i <- 1 to lineIn.next().toInt) {
      val seq = lineIn.next() split ' '
      val answer = solve(seq)
      lineOut(s"Case #$i: $answer")
    }
  }

}