Subj : Re: how to generate a sequence?
To   : comp.programming
From : Gorazd Bozic
Date : Thu Sep 08 2005 04:17 pm

Neo wrote:
> Hi All,
> 
> I have problem, I want to generate all possible (unique) combinations of the 
> following sequence:
....
> Algo. required! Do U have a quick solution in mind???

Here's one:

takeout(X, [X|R], R).
takeout(X, [F|R], [F|S]) :- takeout(X, R, S).

perm([X|Y], Z) :- perm(Y, W), takeout(X, Z, W).
perm([],[]).

Here's an example:

?- findall(X, perm([1,2,3], X), Result).

X = _G423
Result = [[1,2,3], [2,1,3], [2,3,1], [1,3,2], [3,1,2], [3,2,1]]

.