Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
Groups > comp.lang.python > #88323
| Date | 2015-03-30 04:16 -0400 |
|---|---|
| From | Dave Angel <davea@davea.name> |
| Subject | Re: Sudoku solver |
| References | (6 earlier) <ziRRw.1732061$BB2.522910@fx35.am4> <87619j7kbu.fsf@elektro.pacujo.net> <mailman.334.1427698246.10327.python-list@python.org> <mfat14$v08$1@dont-email.me> <CALwzid=zoDano9ZQ7vkk_uVG8kLSBs2822YaTTR4MYNfGmzu8g@mail.gmail.com> |
| Newsgroups | comp.lang.python |
| Message-ID | <mailman.337.1427703431.10327.python-list@python.org> (permalink) |
On 03/30/2015 03:29 AM, Ian Kelly wrote: > On Mon, Mar 30, 2015 at 1:13 AM, Christian Gollwitzer <auriocus@gmx.de> wrote: >> Am 30.03.15 um 08:50 schrieb Ian Kelly: >>> >>> On Sun, Mar 29, 2015 at 12:03 PM, Marko Rauhamaa <marko@pacujo.net> wrote: >>>> >>>> Be careful with the benchmark comparisons. Ian's example can be solved >>>> with the identical algorithm in eight different ways (four corners, left >>>> or right). I ran the example with my recent Python solver and got these >>>> times in the eight cases: >>>> >>>> 884 s >>>> 2.5 s >>>> 13 s >>>> 499 s >>>> 5.9 s >>>> 128 s >>>> 1360 s >>>> 36 s >>> >>> >>> That sounds to me like either a transcription error was made to the >>> puzzle at some point, or there's something wrong with your solver. The >>> whole point of that example was that it was a puzzle with the minimum >>> number of clues to specify a unique solution. >> >> I think Marko meant, that if he creates symmetrically equivalent puzzles by >> rotating / mirroring the grid, he gets vastly different execution times, but >> ends up with the same solution. > > That makes sense, but it is true for all puzzles that there are eight > possible orientations (since it's impossible for a puzzle solution to > be symmetric), and the wording made it sound like he was describing a > property specific to the puzzle that I posted. > But for some puzzles, the 8 timings may be much closer. Or maybe even further apart. Incidentally, there are many other variants of the same puzzle that might matter, beyond those 8. The digits can all be crypto'ed Like replace all 4 with 8, etc. Probably won't matter for any realistic algorithm. The columns can be reordered, in at least some ways. For example, if the first and second columns are swapped, it's a new puzzle, equivalent. Likewise certain rows. The relationship between row, column and box can be rearranged. Some of these are already covered by the rotations proposed earlier, where for a 90 degree rotate, row becomes column and column becomes row. But in a similar way each box could become a column, and so on. All of these rearrangeements will change the order that an algorithm might choose to examine things, and thus affect timings (but not the solution). When I made my own solver years ago, I considered the puzzle to have 9 columns, 9 rows, and 9 boxes. So these 27 lists of 9 could be analyzed. I just came up with a fast way to map those 243 cells back and forth with the original 81. At that point, it no longer mattered which things were rows and which were columns or boxes. -- DaveA
Back to comp.lang.python | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
Sudoku solver Marko Rauhamaa <marko@pacujo.net> - 2015-03-25 13:39 +0200
Re: Sudoku solver John Ladasky <john_ladasky@sbcglobal.net> - 2015-03-25 11:44 -0700
Re: Sudoku solver Ian Kelly <ian.g.kelly@gmail.com> - 2015-03-25 13:05 -0600
Re: Sudoku solver Marko Rauhamaa <marko@pacujo.net> - 2015-03-25 21:37 +0200
Re: Sudoku solver Ian Kelly <ian.g.kelly@gmail.com> - 2015-03-25 14:09 -0600
Re: Sudoku solver Marko Rauhamaa <marko@pacujo.net> - 2015-03-25 22:31 +0200
Re: Sudoku solver Chris Angelico <rosuav@gmail.com> - 2015-03-26 09:40 +1100
Re: Sudoku solver Ian Kelly <ian.g.kelly@gmail.com> - 2015-03-25 18:07 -0600
Re: Sudoku solver BartC <bc@freeuk.com> - 2015-03-27 20:04 +0000
Re: Sudoku solver Abhiram R <abhi.darkness@gmail.com> - 2015-03-26 08:26 +0530
Re: Sudoku solver Ian Kelly <ian.g.kelly@gmail.com> - 2015-03-25 21:24 -0600
Re: Sudoku solver Abhiram R <abhi.darkness@gmail.com> - 2015-03-26 08:58 +0530
Re: Sudoku solver Marko Rauhamaa <marko@pacujo.net> - 2015-03-26 14:13 +0200
Re: Sudoku solver Marko Rauhamaa <marko@pacujo.net> - 2015-03-26 16:15 +0200
Re: Sudoku solver albert@spenarnc.xs4all.nl (Albert van der Horst) - 2015-04-10 23:10 +0000
Re: Sudoku solver Sayth <flebber.crue@gmail.com> - 2015-03-27 20:39 -0700
Re: Sudoku solver BartC <bc@freeuk.com> - 2015-03-28 23:50 +0000
Re: Sudoku solver Chris Angelico <rosuav@gmail.com> - 2015-03-29 11:12 +1100
Re: Sudoku solver BartC <bc@freeuk.com> - 2015-03-29 21:59 +0100
Re: Sudoku solver Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-03-29 22:19 +0100
Re: Sudoku solver BartC <bc@freeuk.com> - 2015-03-29 22:59 +0100
Re: Sudoku solver Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-03-29 14:06 +1100
Re: Sudoku solver Chris Angelico <rosuav@gmail.com> - 2015-03-29 15:10 +1100
Re: Sudoku solver Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-03-29 21:35 +1100
Re: Sudoku solver Chris Angelico <rosuav@gmail.com> - 2015-03-29 21:54 +1100
Re: Sudoku solver BartC <bc@freeuk.com> - 2015-03-29 13:01 +0100
Re: Sudoku solver BartC <bc@freeuk.com> - 2015-03-29 16:23 +0100
Re: Sudoku solver Christian Gollwitzer <auriocus@gmx.de> - 2015-03-29 09:57 +0200
Re: Sudoku solver BartC <bc@freeuk.com> - 2015-03-30 11:54 +0100
Re: Sudoku solver BartC <bc@freeuk.com> - 2015-03-29 12:25 +0100
Re: Sudoku solver Marko Rauhamaa <marko@pacujo.net> - 2015-03-29 21:03 +0300
Re: Sudoku solver Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-03-29 19:26 +0100
Re: Sudoku solver Marko Rauhamaa <marko@pacujo.net> - 2015-03-29 21:33 +0300
Re: Sudoku solver BartC <bc@freeuk.com> - 2015-03-29 22:11 +0100
Re: Sudoku solver Ian Kelly <ian.g.kelly@gmail.com> - 2015-03-30 00:50 -0600
Re: Sudoku solver Christian Gollwitzer <auriocus@gmx.de> - 2015-03-30 09:13 +0200
Re: Sudoku solver Ian Kelly <ian.g.kelly@gmail.com> - 2015-03-30 01:29 -0600
Re: Sudoku solver Marko Rauhamaa <marko@pacujo.net> - 2015-03-30 12:16 +0300
Re: Sudoku solver Dave Angel <davea@davea.name> - 2015-03-30 04:16 -0400
Re: Sudoku solver Ian Kelly <ian.g.kelly@gmail.com> - 2015-03-30 02:57 -0600
Re: Sudoku solver Chris Angelico <rosuav@gmail.com> - 2015-03-30 20:13 +1100
Re: Sudoku solver Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-03-29 22:21 +0100
Re: Sudoku solver BartC <bc@freeuk.com> - 2015-03-29 23:17 +0100
Re: Sudoku solver Seymore4Head <Seymore4Head@Hotmail.invalid> - 2015-03-29 21:40 -0400
Re: Sudoku solver Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-03-26 09:50 +1100
Re: Sudoku solver Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-03-25 23:04 +0000
Re: Sudoku solver Christian Gollwitzer <auriocus@gmx.de> - 2015-03-27 07:40 +0100
Re: Sudoku solver "Frank Millman" <frank@chagford.com> - 2015-03-26 10:19 +0200
Re: Sudoku solver Marko Rauhamaa <marko@pacujo.net> - 2015-03-26 14:26 +0200
Re: Sudoku solver Chris Angelico <rosuav@gmail.com> - 2015-03-26 23:37 +1100
Re: Sudoku solver Ian Kelly <ian.g.kelly@gmail.com> - 2015-03-26 07:15 -0600
Re: Sudoku solver Marko Rauhamaa <marko@pacujo.net> - 2015-03-26 16:23 +0200
Re: Sudoku solver Ian Kelly <ian.g.kelly@gmail.com> - 2015-03-26 09:06 -0600
Re: Sudoku solver Marko Rauhamaa <marko@pacujo.net> - 2015-03-26 17:48 +0200
Re: Sudoku solver Ian Kelly <ian.g.kelly@gmail.com> - 2015-03-26 10:20 -0600
Re: Sudoku solver Marko Rauhamaa <marko@pacujo.net> - 2015-03-26 18:47 +0200
Re: Sudoku solver Dave Angel <davea@davea.name> - 2015-03-26 10:14 -0400
Re: Sudoku solver Chris Angelico <rosuav@gmail.com> - 2015-03-27 01:41 +1100
Re: Sudoku solver Dave Angel <davea@davea.name> - 2015-03-26 11:03 -0400
Re: Sudoku solver Marko Rauhamaa <marko@pacujo.net> - 2015-03-26 17:42 +0200
Re: Sudoku solver Pete Forman <petef4+usenet@gmail.com> - 2015-03-26 22:24 +0000
Re: Sudoku solver Chris Angelico <rosuav@gmail.com> - 2015-03-27 02:21 +1100
Re: Sudoku solver Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2015-03-26 20:42 -0400
Re: Sudoku solver Dave Angel <davea@davea.name> - 2015-03-27 09:14 -0400
Re: Sudoku solver Chris Angelico <rosuav@gmail.com> - 2015-03-28 00:25 +1100
Re: Sudoku solver "Frank Millman" <frank@chagford.com> - 2015-03-27 15:35 +0200
Re: Sudoku solver Marko Rauhamaa <marko@pacujo.net> - 2015-03-27 15:56 +0200
Re: Sudoku solver Dave Angel <davea@davea.name> - 2015-03-27 10:09 -0400
Re: Sudoku solver sohcahtoa82@gmail.com - 2015-03-27 11:18 -0700
Re: Sudoku solver Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-03-28 12:46 +1100
Re: Sudoku solver Larry Hudson <orgnut@yahoo.com> - 2015-03-27 16:48 -0700
Re: Sudoku solver Chris Angelico <rosuav@gmail.com> - 2015-03-28 01:07 +1100
Re: Sudoku solver Chris Angelico <rosuav@gmail.com> - 2015-03-28 01:19 +1100
Re: Sudoku solver Gregory Ewing <greg.ewing@canterbury.ac.nz> - 2015-03-28 14:13 +1300
Re: Sudoku solver Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-03-28 12:40 +1100
Re: Sudoku solver Ian Kelly <ian.g.kelly@gmail.com> - 2015-03-28 02:24 -0600
Re: Sudoku solver Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-03-27 16:03 +0000
Re: Sudoku solver Virgil Stokes <vs@it.uu.se> - 2015-03-28 19:36 +0100
Re: Sudoku solver Dave Angel <davea@davea.name> - 2015-03-27 09:48 -0400
Re: Sudoku solver Dave Angel <davea@davea.name> - 2015-03-27 09:52 -0400
Re: Sudoku solver Chris Angelico <rosuav@gmail.com> - 2015-03-28 00:58 +1100
Re: Sudoku solver mr.smittye@gmail.com - 2015-03-29 16:39 -0700
Re: Sudoku solver Marko Rauhamaa <marko@pacujo.net> - 2015-03-30 12:24 +0300
csiph-web