FileFixIt.scala

object Main {

  def toDirectories(path:String):Set[String] = {
    path.split("/").drop(1).
      foldLeft(List[String](""))(
        (acc:List[String], x:String) => {(acc.head + "/" + x) :: acc}
      ).init.toSet
  }

  def childSets(directories:Set[String]):Set[String] = {
    directories.map(toDirectories).foldLeft(Set[String]()) (
      (acc, x) => {x ++ acc}
    )
  }

  def solve(exist:Set[String], needed:Set[String]) = {
    (childSets(needed) -- childSets(exist)).size
  }

  def main(args: Array[String]) {
    val writer = new java.io.PrintWriter("a-large.out")
    try {
      process(io.Source.fromFile("A-large-practice (4).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 Array(existNum, neededNum) = lineIn.next().split(" ").map(_.toInt)
      val exist = for (i <- 0 until existNum) yield lineIn.next()
      val needed = for (i <- 0 until neededNum) yield lineIn.next()

      lineOut(s"Case #$i: ${solve(exist.toSet, needed.toSet)}")
    }
  }
}