"double post", not "dinner post". Damn. Email needs an edit function and no autocorrect.
On Mon, Jul 20, 2020, 1:09 PM David Storrs <[email protected]> wrote: > First off, if this was an intentional dinner post, well played. :> > > > If you don't want to use built-in functions, I would look at using a hash > to track what you've already seen and then cons things together depending > on if they're in the hash. > > For the second, maybe recur through the list using a hash to track the > most recent index of each item, then pop back up through the recursion > consing things together based on whether you're at the specified index. > That's my first thought, anyway. > > > On Mon, Jul 20, 2020, 12:04 PM JJ C <[email protected]> wrote: > >> In Beginning Student with List Abbreviations >> >> I am struggling to come up with functions to remove duplicates from a >> list while maintaining the order of the list. >> >> one function to remove duplicates from the left, >> >> i.e. 1 2 1 3 2 4 5 -> 1 2 3 4 5 >> >> and one from the right. >> >> i.e. 1 2 1 3 2 4 5 -> 1 3 2 4 5 >> >> What are the functions for removing duplicates from each left and right >> side? If you need to, use helper functions and append, cond, cons, equal?, >> etc but not using reverse or any built-in functions. >> >> -- >> You received this message because you are subscribed to the Google Groups >> "Racket Users" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/racket-users/6049507b-094e-43c9-9dda-28237fcb57d8n%40googlegroups.com >> <https://groups.google.com/d/msgid/racket-users/6049507b-094e-43c9-9dda-28237fcb57d8n%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> > -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/racket-users/CAE8gKoepLmKVqm1hJWun5eQDmCWTJYFzQB59tukgaOvufGOAzw%40mail.gmail.com.
