逆FizzBuzz

逆FizzBuzzをScalaで。

object ReverseFizzBuzz extends App {
  def fb(n:Int):Stream[Option[(Int, String)]] = {
      if(n%15 == 0) Some((n,"FizzBuzz"))
      else if(n%3==0) Some((n,"Fizz"))
      else if(n%5==0) Some((n,"Buzz"))
      else None
  }#::fb(n+1)

  def find(input:Array[String]):String = {
    val list = fb(1).take(15*(1+scala.math.ceil(input.length/7).toInt)).collect{case Some(a) => a}
    (0 until list.length).flatMap { i =>
      val sub = list.slice(i, i + input.length)
      if(sub.map(_._2).corresponds(input){(a,b) => a==b}) Some(sub.map(_._1)) else None
    }.foldLeft("NotFound"){(z,l) =>
      if(l.last-l.head < z.last-z.head) l.mkString(",") else z
    }
  }
  println(find(io.StdIn.readLine.split(",").map(_.trim)).mkString)
}