Message #574

From: Roice Nelson <roice3@gmail.com>
Subject: Re: A Hyperminx solution approach (was [MC4D] Thibaut Kirchner)
Date: Wed, 17 Sep 2008 22:30:02 -0500

Yep, shift+ctrl+clicking does the piece finding functionality, and
left/right clicking distinguishes between the two complementary cases you
mention…
Roice

On Wed, Sep 17, 2008 at 9:42 PM, Melinda Green <melinda@superliminal.com>wrote:

> Roice,
>
> You already implemented the show-the-cubie-that-goes-here functionality,
> right? In other words, the compliment to the
> show-me-where-this-cubie-belongs feature. Without this, I suspect that a
> great deal of a potential solver’s time would be spent searching. Even
> still I expect it will take months but at least the bulk of the mindless
> work can be eliminated.
>
> -melinda
>
>
> Roice Nelson wrote:
> > Hi Thibaut,
> >
> > Welcome! There are a lot of topics floating around (thanks for the
> > parity writeup by the way), but here I’m only replying about your
> > desire to tame Magic120Cell, which we’ve also been calling Hyperminx.
> > I just uploaded a single line code change to the Hyperminx program
> > which I think could greatly help anyone attempting a full solution.
> > The change is that when you switch puzzle types, e.g. from a 2-color
> > puzzle to a 12-color puzzle, the internal state of the puzzle won’t
> > reset. I am copying an email below that I sent to Nelson a few months
> > ago describing the motivation for this. I still haven’t quantified
> > the benefit I perceive would come from this approach, but it hopefully
> > might turn a "taking years" solution into a "taking months" one…
> >
> > All the best,
> > Roice
> >
> > ———- Forwarded message ———-
> > From: *Roice Nelson* <roice@gravitation3d.com<roice%40gravitation3d.com>
> > <mailto:roice@gravitation3d.com <roice%40gravitation3d.com>>>
> > Date: Jun 2, 2008 8:16 PM
> > Subject: Re: One more suggestion
> > To: Nelson Garcia <spel_werdz_rite@hotmail.com<spel_werdz_rite%40hotmail.com>
> > <mailto:spel_werdz_rite@hotmail.com <spel_werdz_rite%40hotmail.com>>>
> >
> >
> > Hey Nelson,
> >
> > So in short, my thought was to take advantage of solving one of the
> > simpler puzzles first as a path towards solving the full puzzle. This
> > would have 2 big advantages. The first is that for the majority of
> > the solution, one would work with a smaller number of colors. The
> > second (less obvious but possibly more dramatic) is that the number of
> > moves to do a full solution would decrease, and here is a little more
> > explanation on that…
> >
> > In computer science, a classic problem is sorting an array of numbers,
> > and there are slower and faster ways to do it. If you have 8 items in
> > a list, it doesn’t matter so much how you sort because the cost
> > difference, although there, won’t balloon to extreme proportions. But
> > when you have 15x as many items in the list (120), the way you
> > sort becomes more important (often the slowness of an approach doesn’t
> > scale linearly, so instead of being 15x slower, it might be 225x
> > slower). There is something called "quick sort", which (roughly
> > speaking) doesn’t sort items in a list one by one, but first moves
> > items into the general area they will ultimately go, and later makes
> > further passes to complete the sorting in the smaller areas. What I’m
> > describing as a suggested approach isn’t really a quicksort, but is
> > loosely based on the idea of moving pieces to an area, then working on
> > the smaller areas later.
> >
> > I should point out I don’t think it would be necessary to fully solve
> > the smaller puzzle. It could be a waste of time to worry about
> > orientations at that stage, and so maybe better to focus only on
> > positions since the pieces will have to be moved around again later.
> > On the other hand, orienting them early on could make later work
> > easier. I’m not sure what I would do on that yet.
> >
> > I think the rings or 4-cube cells puzzles might be best suited as the
> > puzzle to solve first, because unlike the layers puzzle, the different
> > sets are more similar. The tori puzzle might be a bad choice because
> > it is only breaking the world up into 2 big areas, but maybe the gains
> > would still be as big - I’m not sure. The antipodal puzzle is truly a
> > bad choice though because the sets of similarly colored cells are not
> > connected.
> >
> > You could also choose to do it in 3 steps. You could do the tori
> > puzzle, then switch to the rings or 4-cube cells puzzle, then finally
> > switch to the full puzzle. Note that after the first step of moving
> > pieces into the correct areas of the tori puzzle, you have only really
> > actively moved half of the puzzle pieces, yet the other half are in
> > their area now as well. In effect, you have obtained a lot of work for
> > free!
> >
> > Now, when you switch puzzles in the program, it currently resets the
> > puzzle (maybe this should change), so you can’t do what I’m describing
> > with the UI. But you can edit the integer representing the puzzle
> > type in the log file at any point and it would work. Even on the
> > simpler puzzles, the internal state representation still contains the
> > full 120 colors on all the cells. I intentionally made that the case,
> > knowing this meant log files that have solved one of the easier
> > puzzles still won’t look very pristine.
> >
> > That’s it. I could analyze the benefits further (actually try to
> > estimate what the differences in moves required might be), but these
> > are my loose thoughts on it so far, and I have the feeling that the
> > benefits in time-complexity of solution are definitely worth it.
> >
> > Roice
>
>
>