gistfile1.java

val a = 1 :: 2 :: 3 :: 4 :: 3 :: 2 :: 5 :: 4 :: Nil


def r[A](h: List[A], t: List[A]): List[A] = {
    if(t isEmpty)
        return h
    if(t.tail exists(i => i == t.head))
        h ::: r(Nil, t.tail)
    else
        h ::: (t.head :: Nil) ::: r(Nil, t.tail)
}


println(r(Nil, a reverse) reverse)