Selection sort implementation in Scala

selection_sort.scala

// Inmperative version
//
def selectionSort(list: Array[Int]): Unit {
  def swap(list: Array[Int], i: Int, j: Int) {
    var tmp = list(i)
    list(i) = list(j)
    list(j) = tmp
  }
  
  var i = 0
  while(i < (list.length - 1)) {
    var min = i
    var j = i + 1
    
    while (j < list.length) {
      if(list(j) < list(min)) {
        min = j
      }
      j += 1
    }
    
    swap(list, i, min)
    i += 1
  }
}


// Functional / Recursive version
//
def selectionSort2(list: List[Int]): List[Int] = {
  
  if(list.length == 1) list
  else {
    // Pseudo code
    // list.min :: selectionSort2(list.everything_but_min)
  }
}

Even though, when coding Scala, I'm used to prefer functional programming style (via combinators or recursion) over imperative style (via variables and iterations), THIS TIME, for this specific problem, old school imperative nested loops result in simpler code for the reader. I don't think falling back to imperative style is a mistake for certain classes of problems (such as sorting algorithms which usually transform the input buffer (like a procedure) rather than resulting to a new sorted one

My solution on https://github.com/angiolep/algorithms

def selectionSort(list:List[Int]):List[Int] = {
  @tailrec
  def selectSortHelper(list:List[Int], accumList:List[Int] = List[Int]()): List[Int] = {

    list match {
      case Nil => accumList
      case _ => {
        val min  = list.min
        val requiredList = list.filter(_ != min)
        selectSortHelper(requiredList, accumList ::: List.fill(list.length - requiredList.length)(min))
      }
    }
  }
  selectSortHelper(list)
}