practice in scala. QuickSort

qs.scala

val ar = Array(79,56,89,100,1,2,6,5,90,21,26,75,35,67,66,65,81,10,0)//適当な配列 (0 <= x <= 100)

def qs(a:Array[Int]):Array[Int] = {
  if(a.length == 1) return a
  val pivot = if(a(0) > a(1)) a(0) else a(1)
  val a0 = qs(a.filter( _ < pivot))
  val a1 = qs(a.filter( _ >= pivot))
  Array.concat(a0,a1)
}

qs(ar).foreach{
  println
}