From: "David A. Black" <dblack@...>
Date: 2005-12-06T12:16:34+09:00
Subject: Re: Speed Golf - Remove Early Dups

Hi --

On Tue, 6 Dec 2005, Phrogz wrote:

> SUMMARY
> What's the fastest and/or shortest you can turn this:
>    in = ["i", "v", "w", "e", "l", "d", "u", "f", "e", "v", "f", "e",
> "d", "e", "w", "d"]
>
> into this:
>    ["i", "l", "u", "v", "f", "e", "w", "d"]
> ?
>
>
> DETAILS
> The goal is, given a stream of items, to produce the same ordered
> stream with no duplicates, where the relative position of the last item
> wins. The shortest (and fastest?) for me turns out to be simply:
>    in.reverse.uniq.reverse

This entry is not in contention on shortness or speed (don't even bother
to benchmark it -- it's completely off the charts), but I just thought it
looked really cool :-)

  a.inject([]){|r,*b|r-b+b}


David
__
David A. Black
dblack@wobblini.net

"Ruby for Rails", forthcoming from Manning Publications, April 2006!