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martin

2005-06-09, 8:57 pm

Hello,

I want to generate all lists that consit four pairs of numbers (1..9). So
the list should 36 elements. I wanted to find all permutations of a set
[1,1,1,1,2,2,2,2,......,8,8,8,8,9,9,9,9] but it's not a good solutions
becuase then I get lists that look the same but are different permutations
of the set. Because of that fact I get much more solutions than I want and
testing generated lists takes too much time. Thanks for help

regard,
martin


tmp123

2005-06-10, 3:59 pm

A simple method, I hope it useful:

| p([[A|B]|Q],A,QR) :-
| B=[] -> QR=Q; QR=[B|Q].
| p([H|Q],A,[H|QR]) :- p(Q,A,QR).
|
| r([],[]).
| r(I,[H|Q]) :-
| p(I,H,T),
| r(T,Q).


Filter of students looking for skip homework: how to use it.

Kind regards.

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