P20 (*) Remove the Kth element from a list. Return the list and the removed element in a Tuple. Elements are numbered from 0. Example: scala> removeAt(1, List('a, 'b, 'c, 'd)) res0: (List[Symbol], Symbol) = (List('a, 'c, 'd),'b)

removeAt.scala

def removeAt[A](n: Int, input: List[A]): (List[A], A) = {
  def removeAtHelper(input: List[A], p: Int = n): List[A] = input match{
    case Nil => Nil
    case h :: t => if(p > 0) h :: removeAtHelper(t, p - 1) else t
  }
  def symbol(input: List[A], q: Int): Option[A] = input match {
    case Nil => Nothing
    case h :: t => if(q > 0) symbol(t, q - 1) else t.headOption.getOrElse(Nothing)
  }
(removeAtHelper(input), symbol(input))
}