Subj : Re: Algorithm to generate permutation for a non sequential single array
To   : comp.programming
From : mmarin1m@hotmail.com
Date : Tue Jul 05 2005 10:33 am



Thad Smith wrote:
> mmarin1m@hotmail.com wrote:
>
> > Hi all,
> >
> > I'm looking for an algorithm that would generate all permutations for a
> > given non sequential list. As an example:
> >
> > Given the list 125, 126, 5, 88 and 33, all permutations must be
> > generated in that sequence.
> >
> > The perfect algorithm would yields the following matrix:
> >
> > 125, 126, 5, 88, 33
> > 125, 126, 5, 88
> > 126, 5, 88, 33
> > 125, 126, 5
> > 125, 126, 88
> > 125, 126, 33
> > 125, 5, 88
> > 125, 5, 33
> > 125, 88, 33
> > 126, 5, 88
> > 126, 5, 33
> > 126, 88, 33
> > 5, 88, 33
> > 125, 126
> > 125, 5
> > 125, 88
> > 125, 33
> > 126, 5
> > 126, 88
> > 126, 33
> > 5, 88
> > 5, 33
> > 88, 33
> > 125
> > 126
> > 5
> > 88
> > 33
>
> What you have illustrated is subsets of the original set, not
> permutations.  Are the subsets {125,126,5,33}, {125,126,88,33}, and
> {125,5,88,33} intentionally missing from the output of the perfect
> algorithm?  If not, Richard's suggestion of binary mapping should work well.
>
> Thad

You are right, my perferct algoritm isn't so perfect after all! Yes,
the subsets {125, 126, 5, 33} and {125, 126, 88, 33} are valid
permutations.

would the same binary mapping work as well?

Thanks,

Michel

.