P11 (*) Modified run-length encoding.

 def encodeModified[T] (l :List[T]) : List[Any] = {

    pack(l).map(sublist => if (sublist.length==1) sublist.head else  (sublist.length, sublist.head))
}

     |      |      |      | encodeModified: [T](List[T])List[Any]
scala> encodeModified(List('a, 'a, 'a, 'a, 'b, 'c, 'c, 'a, 'a, 'd, 'e, 'e, 'e, 'e))

res7: List[Any] = List((4,'a), 'b, (2,'c), (2,'a), 'd, (4,'e))