[Haskell-cafe] Re: [Haskell-beginners] Re: permuting a list

Daniel Fischer daniel.is.fischer at web.de
Sat Feb 14 11:46:52 EST 2009


Am Samstag, 14. Februar 2009 16:37 schrieb Heinrich Apfelmus:
>
> That of course begs the question whether there is a faster but purely

No, it didn't beg any question. (Sorry for being a humourless pedant here)

> functional algorithm for generating random permutations without indexes
> and arrays?
>
> The answer is a resounding "yes" and the main idea is that shuffling a
> list is *essentially the same* as sorting a list; the minor difference
> being that the former chooses a permutation at random while the latter
> chooses a very particular permutation, namely the one that sorts the input.
>
> For the full exposition, see
>
>    http://apfelmus.nfshost.com/random-permutations.html

Excellent work, thanks.
>
>
> Regards,
> apfelmus

Cheers,
Daniel


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