Re: Too many permutations computed

[Heime]

------- Original Message -------
On Friday, August 4th, 2023 at 10:13 AM, Emanuel Berg <incal@dataswamp.org> 
wrote:


> uzibalqa wrote:
> 
> > > Again you can check out these two
> > > 
> > > https://dataswamp.org/~incal/emacs-init/perm.el
> > > https://www.emacswiki.org/emacs/StringPermutations
> > > 
> > > but after spending so much time on your own solution I get it
> > > you want to complete it ...
> > 
> > There are many algorithms out there. You should mention the
> > kind of algorithm you are implementing.
> 
> 
> Not sure it has one? But it is for permutation of list
> elements in general, the rest is just using it for the string
> use case. 

It does use a published technique, but did not take time to determine 
which one is it.  If I can space some time, I can check things out. 

> Maybe Emacs should have a built-in permutation
> function BTW, and a ditto library with helpers, e.g.
> for strings ...

That would make sense because permutations is quite a standard thing
today with a number of algorithms.  The implementation to use depends
on how much complication you are willing to accept programatically.
The more complicated, the more benefits you get.
 
> > I am using the original algorithm bf Robert Heap (1964).
> > It is not the common implementation you see because what
> > I have seen is the implementation of a simpler algorithm
> > (programatically), but which is not optimal in the way
> > Robert constructed it.
> 
> 
> Okay, well, see if you can get it to work then ...
> 
> --
> underground experts united
> https://dataswamp.org/~incal