[Haskell-cafe] I need a hint in list processing
fernanbolando at mailc.net
Sun Jun 14 04:32:33 EDT 2009
On Sun, Jun 14, 2009 at 4:13 PM, Erik de Castro
Lopo<mle+hs at mega-nerd.com> wrote:
> Fernan Bolando wrote:
>> Hi all
>> If I have a number of list
>> 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?
> Well you could simply concatenate all the lists using the (++) operator
> and then use Data.List.nub:
> to remove duplicates.
Data.List> nub [2,3,1,2,2,3,4,1,2,3]
that is not exactly what I want. list1 only has 2,3 has elements and list2 only
has elements 1,2...this means the first element should only be 2 or 3 and
the second element should only have 1 or 2...etc
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