Combination Examples

Combo.scala

object Combo extends App {
  val vars   = List("a", "b", "c", "d")
  val list   = vars map (e => ("-%s".format(e), "+%s".format(e)))
  val len    = list.size
  val combos = math.pow(2, len).toInt

  for (i <- 0 until combos) {
    for (j <- 0 until len) {
      val (off, on) = list(j)
      print ("%s ".format(if ((i >> j) % 2 == 0) off else on))
    } // for
    println
  } // for
}