Show that recursive call need to be final or private (avoid overriding)

tailrec.scala

  class C {
    def fact(n: Int, result: Int): Int ={
      println("super")
      if(n == 0) result else fact(n - 1, n * result)
    }

  }


  class C2 extends C {
    override def fact(n: Int, result: Int): Int = {
      println("sub")
      2 * super.fact(n, result)
    }
  }

  println((new C).fact(5, 1))

  println((new C2).fact(3, 1))