Give meaningful names, improve code, write some tests.

MasterOfNames.scala

  def a(b: List[AnyRef]): List[String] =
    b.foldLeft(List[String]())((c, d) => d match {
      case null => c
      case e: String => c :+ e
      case f: List[AnyRef] => c ++ a(f)
    })

  def g(h: List[String]) =
    h.foldLeft(List[String]())((i, j) => i.lastOption match {
      case Some(`j`) => i
      case _ => i :+ j
    })