scala/ScalaBook/chapter-02/set.scala

import scala.util.Random
var B : Set[Int] = Set()
for (i<-1 to 50) B = B ++ Set(i)
var position = 0
var rnd = new Random()
do {
   var entrant = rnd.nextInt(50)+1
   if ( B.contains(entrant) ) {
     position += 1
     print(position); print(" ");
     println(entrant)
     B -=  entrant
   }
} while (! B.isEmpty)