Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.lang.python > #87979

Re: Sudoku solver

Path csiph.com!v102.xanadu-bbs.net!xanadu-bbs.net!feeder.erje.net!eu.feeder.erje.net!eternal-september.org!feeder.eternal-september.org!mx02.eternal-september.org!.POSTED!not-for-mail
From Marko Rauhamaa <marko@pacujo.net>
Newsgroups comp.lang.python
Subject Re: Sudoku solver
Date Wed, 25 Mar 2015 22:31:02 +0200
Organization A noiseless patient Spider
Lines 31
Message-ID <87iodoakft.fsf@elektro.pacujo.net> (permalink)
References <87r3sdnw5t.fsf@elektro.pacujo.net> <4e81bdb9-52db-46e6-b449-d4241cb2a3f2@googlegroups.com> <87twx8amww.fsf@elektro.pacujo.net> <mailman.159.1427314248.10327.python-list@python.org>
Mime-Version 1.0
Content-Type text/plain
Injection-Info mx02.eternal-september.org; posting-host="ff5cf27ef3d5b31f034d3b72bdc27a41"; logging-data="11514"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX1+Ub8Aq4dpnoyGhIidRqiu0"
User-Agent Gnus/5.13 (Gnus v5.13) Emacs/24.3 (gnu/linux)
Cancel-Lock sha1:G9tt+uYJnx8IBx7P/ZpddjgWVIM= sha1:nlUqhGWvR1xm/D0hNqwSmEomZKc=
Xref csiph.com comp.lang.python:87979

Show key headers only | View raw

Ian Kelly <ian.g.kelly@gmail.com>:

> The test puzzle that you posted has 23 values already filled in. How
> does it perform on harder puzzles with only 17 clues (the proven
> minimum)? One would expect it to be around a million times slower.

Just try it. The example had a minimum of clues (drop one clue and
you'll get multiple solutions).

<URL: http://www.telegraph.co.uk/news/science/science-news/9359579/W
orlds-hardest-sudoku-can-you-crack-it.html> mentions this puzzle:

========================================================================
8 . . . . . . . .
. . 3 6 . . . . .
. 7 . . 9 . 2 . .
. 5 . . . 7 . . .
. . . . 4 5 7 . .
. . . 1 . . . 3 .
. . 1 . . . . 6 8
. . 8 5 . . . 1 .
. 9 . . . . 4 . .
========================================================================

It takes about 2 seconds for my Python program to find the answer but it
spends a total of 110 seconds to exhaust the problem space.

The analogous C program finished the whole thing in 200 milliseconds.


Marko

Back to comp.lang.python | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

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