RationalNumberTree

gistfile1.scala

package lascala.codejam.enshahar 

object RationalNumberTree {
  lazy val tree:Stream[List[(BigInt, BigInt)]] =
    List((BigInt(1),BigInt(1))) #:: tree.map( _.flatMap { case (x,y) => List((x,x+y), (x+y, y)) } )
  
  val flattree = tree.flatten
  
  lazy val nat:Stream[BigInt] = 1 #:: nat.map(_+1)

  lazy val nat2:Stream[Int] = 1 #:: nat2.map(_+1)
  
  val flatTreeWithIdx = flattree.zip(nat)
  
  def process(s:Array[String]):String = s match {
    case Array("1", n) =>
			val ((p,q), _) = flatTreeWithIdx(n.toInt-1)
			s"${p} ${q}"
    case Array("2", p, q) =>
			val v = flatTreeWithIdx.find { case ((p1, q1), r) => p1 == BigInt(p) && q1 == BigInt(q) }
      s"${v.get._2}"
  }

  def main(args: Array[String]) {
    val writer = new java.io.PrintWriter("a.out")
    try {
      // val lines = io.Source.fromFile("B-small-practice.in").getLines.drop(1)
      val lines = io.Source.fromFile("B-large-practice.in").getLines.drop(1)
      // val lines = io.Source.fromFile("ex.in").getLines.drop(1)
      val answers = lines.map(_ split ' ').map(process)
			for {
				(s, idx) <- answers.zipWithIndex
			} { writer.println(s"Case #${idx+1}: ${s}") }
    } finally {
      writer.flush(); writer.close()
    }
  }
}