[Haskell-cafe] I need a hint in list processing

Miguel Mitrofanov miguelimo38 at yandex.ru
Sun Jun 14 04:51:20 EDT 2009


ghci> map reverse $ foldM (\answer list -> [x:answer | x <- list, not  
$ x `elem` answer]) [] [[2,3], [1,2], [2,3,4], [1,2,3]]
[[2,1,4,3],[3,1,4,2],[3,2,4,1]]

On 14 Jun 2009, at 12:06, Fernan Bolando wrote:

> Hi all
>
> If I have a number of list
> example
> list1 = [2,3]
> list2 = [1,2]
> list3 = [2,3,4]
> list4 = [1,2,3]
>
> I want to create a list from the list above with n elements,
> non-repeating and each elements index represents 1 of the elements
> from the corresponding list so for the above input I would get.
>
> a = [3,2,4,1]
>
> ofcourse there may be several set that will satisfy the problem, so a
> list of list that satisfies would be good.
>
> How do I do this in haskell? or is there a code snippet that seems to
> work similarly?
>
> thanks
> fernan
>
> -- 
> http://www.fernski.com
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