decode(list l)
{
    integer c, e;
    data al, s;

    al = "abcdefghijklmnopqrstuvwxyz";
    for (, e in l) {
        s.append(c = al[e]);
        al.delete(e).insert(0, c);
    }

    s;
}

encode(data s)
{
    integer c, e;
    data al;
    list l;

    al = "abcdefghijklmnopqrstuvwxyz";
    for (, c in s) {
        l.append(e = al.place(c));
        al.delete(e).insert(0, c);
    }

    l;
}

main(void)
{
    for (, text s in list("broood", "bananaaa", "hiphophiphop")) {
        list l;

        l = encode(s);
        l.ucall(o_, 1, " ");
        o_(": ", decode(l), "\n");
    }

    0;
}