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

Groups > comp.lang.python > #88050

Re: Sudoku solver

Path csiph.com!v102.xanadu-bbs.net!xanadu-bbs.net!feeder.erje.net!eu.feeder.erje.net!newsfeed.xs4all.nl!newsfeed2a.news.xs4all.nl!xs4all!post.news.xs4all.nl!not-for-mail
Return-Path <ian.g.kelly@gmail.com>
X-Original-To python-list@python.org
Delivered-To python-list@mail.python.org
X-Spam-Status OK 0.081
X-Spam-Evidence '*H*': 0.84; '*S*': 0.00; 'second.': 0.09; 'solution,': 0.09; 'docstring': 0.16; 'program?': 0.16; 'python- based': 0.16; 'solver': 0.16; 'url:ics': 0.16; 'url:py': 0.16; 'wrote:': 0.18; 'otherwise,': 0.22; 'logical': 0.24; 'question': 0.24; 'sort': 0.25; '&gt;': 0.26; 'holds': 0.26; 'second': 0.26; 'url:edu': 0.26; 'header:In-Reply-To:1': 0.27; 'am,': 0.29; 'statement': 0.30; 'message-id:@mail.gmail.com': 0.30; 'usually': 0.31; 'another': 0.32; 'could': 0.34; 'one,': 0.35; 'received:google.com': 0.35; 'described': 0.36; 'returning': 0.36; 'sequence': 0.36; 'possible': 0.36; 'should': 0.36; 'error.': 0.37; 'being': 0.38; 'to:addr:python-list': 0.38; 'skip:& 20': 0.39; 'to:addr:python.org': 0.39; 'solve': 0.60; 'reach': 0.63; 'here': 0.66; 'between': 0.67; 'mar': 0.68; '26,': 0.68; 'presented': 0.69; 'trial': 0.83; '2015': 0.84; 'water.': 0.84
DKIM-Signature v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; bh=8njKDmHdy7k/RqNP7pTZXgluUPb1gJbkWxMmj0QTV08=; b=0me6tsv9YBoFbyxYX/e1mv9HsdVrT6RDi146/8ODgKlxVdt1OaloHxQ4bm4HziX3MP 8HXn+I0sXdddMxI0c5aUxLtqYCnDxYzh50NCkObE+Sxj6knnv7vFtWt0fHc7gdOHP9py RW2UYdv6Jc2vdrjxluqjguYVGFn39e6+mYU9EV/2t9Ge6fCo+UUnQtwTOSjKMBrRKTE3 +PTIiPK73TQ1JiQsipdoFwg1vRGUMnesdbMfcBZI29dxwoN6xYxkV3SDs/O6kSpODNlK fY8aUfJcg3IWLP6JdaBfUgLq73xowIyP6dYP9rGT9O6MQyPQTlTLhjy0Zn9YxHsdT4aX qr7w==
MIME-Version 1.0
X-Received by 10.66.65.234 with SMTP id a10mr27248683pat.120.1427375755257; Thu, 26 Mar 2015 06:15:55 -0700 (PDT)
In-Reply-To <87fv8sndw1.fsf@elektro.pacujo.net>
References <87r3sdnw5t.fsf@elektro.pacujo.net> <mailman.188.1427358005.10327.python-list@python.org> <87fv8sndw1.fsf@elektro.pacujo.net>
Date Thu, 26 Mar 2015 07:15:55 -0600
Subject Re: Sudoku solver
From Ian Kelly <ian.g.kelly@gmail.com>
To Python <python-list@python.org>
Content-Type multipart/alternative; boundary=001a11363698da754a051230d000
X-BeenThere python-list@python.org
X-Mailman-Version 2.1.19
Precedence list
List-Id General discussion list for the Python programming language <python-list.python.org>
List-Unsubscribe <https://mail.python.org/mailman/options/python-list>, <mailto:python-list-request@python.org?subject=unsubscribe>
List-Archive <http://mail.python.org/pipermail/python-list/>
List-Post <mailto:python-list@python.org>
List-Help <mailto:python-list-request@python.org?subject=help>
List-Subscribe <https://mail.python.org/mailman/listinfo/python-list>, <mailto:python-list-request@python.org?subject=subscribe>
Newsgroups comp.lang.python
Message-ID <mailman.197.1427375759.10327.python-list@python.org> (permalink)
Lines 62
NNTP-Posting-Host 2001:888:2000:d::a6
X-Trace 1427375759 news.xs4all.nl 2859 [2001:888:2000:d::a6]:59304
X-Complaints-To abuse@xs4all.nl
Xref csiph.com comp.lang.python:88050

Show key headers only | View raw

[Multipart message — attachments visible in raw view] - view raw

On Mar 26, 2015 6:31 AM, "Marko Rauhamaa" <marko@pacujo.net> wrote:
>
> "Frank Millman" <frank@chagford.com>:
>
> > Here is another python-based sudoku solver -
> >
> > http://www.ics.uci.edu/~eppstein/PADS/Sudoku.py
> >
> >>From its docstring -
> >
> > "A proper Sudoku puzzle must have a unique solution, and it should be
> > possible to reach that solution by a sequence of logical deductions
> > without trial and error.
>
> I don't think that statement holds water. Trial-and-error is at the
> basis of deduction (reductio ad absurdum). The human solver employs it
> in their head. The question is, what is the difference between
> pen-and-paper and in-your-head for a computer program?

It's an accurate characterization of the sort of puzzles that are typically
presented as sudoku. I don't think that I have used trial and error, in my
head or otherwise, in any sudoku I have ever solved.

> > It solved Marko's original puzzle and Ian's puzzle in less than a
> > second. It could not solve Marko's second one, returning "impossible"
> > immediately.

Perhaps this is why that puzzle was described as being so difficult: it
required steps that human solvers don't usually take.

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