Google Code Jam 2014 Qualification Round A Magic Trick

magic_trick.scala

object magic_trick extends App {
    def solve(first_answer: Int, first_cards: List[List[Int]], second_answer: Int, second_cards: List[List[Int]]): String = {
        val first_choice = first_cards(first_answer - 1)
        val second_choice = second_cards(second_answer - 1)
        val answer = (first_choice.toSet & second_choice.toSet).toList
        answer match {
            case head :: Nil => head.toString
            case Nil => "Volunteer cheated!"
            case head :: tail => "Bad magician!"
        }
    }

    //////////
    // main //
    //////////
    if (args.length > 0) Console.setIn(new java.io.FileInputStream(args(0)))
    if (args.length > 1) Console.setOut(new java.io.FileOutputStream(args(1)))

    for (t <- 1 to readInt) {
        val first_answer = readInt
        val first_cards = for (row <- 1 to 4) yield readLine.split(" ").map(_.toInt).toList
        val second_answer = readInt
        val second_cards = for (row <- 1 to 4) yield readLine.split(" ").map(_.toInt).toList
        println("Case #" + t + ": " + solve(first_answer, first_cards.toList, second_answer, second_cards.toList))
    }
}