FAQ   Search   Memberlist   Usergroups   Register   Profile   Log in          Games  Calendar Log in to check your private messages    SOLVING TECHNIQUE INDEX Goto page 1, 2, 3  Next          Sudoku Programmers Forum Index -> Solving sudoku View previous topic :: View next topic   Author Message Ruud Site Admin Joined: 17 Sep 2005 Posts: 708 : Location: Netherlands Items Posted: Wed Nov 02, 2005 12:56 pm    Post subject: SOLVING TECHNIQUE INDEX I've experienced that it can sometimes be difficult to find the right topics when you want to know how a particular technique works. Often the subject title does not cover the interesting information it contains. Some of the techniques have only been discussed in the players forum. In those cases a link to the relevant topics is present. Also, when a more recent or complete definition is present elsewhere (for example on the players forum), an external link has been added to the list of local forum links. You are invited to start a discussion on these topics here in the programmers forum, so we can replace these external links. SUDOPEDIA Most solving techniques are now also explained in Sudopedia, with examples and links to related solving techniques. http://www.sudopedia.org/wiki/Solving_technique TERMINOLOGY http://www.sudopedia.org/wiki/Terminology http://www.sudocue.net/glossary.php http://www.playr.co.uk/sudoku/dictionary.php http://en.wikipedia.org/wiki/List_of_Sudoku_terms_and_jargon SOLVING GUIDES For those new to Sudoku, here are several sites with good explanations of solving techniques which include all of the simpler techniques: http://www.angusj.com/sudoku/hints.php http://www.sadmansoftware.com/sudoku/techniques.htm http://www.palmsudoku.com/pages/techniques-overview.php http://www.sudocue.net/guide.php http://www.scanraid.com/BasicStrategies.htm http://www.stolaf.edu/people/hansonr/sudoku/explain.htm http://homepages.cwi.nl/~aeb/games/sudoku/ http://www.wikihow.com/Solve-a-Sudoku http://www.sudoku.com/howtosolve.htm http://www.sudoku.org.uk/PDF/Solving_Sudoku.pdf http://www.sudokuoftheday.com/pages/techniques-overview.php http://en.wikipedia.org/wiki/Sudoku (general Sudoku article) http://www.sudokuassistant.co.uk/solving/solving-sudoku.htm http://www.brainbashers.com/sudokuhelp.asp SOLVING TECHNIQUE INDEX Line-Box Interactions http://www.setbb.com/sudoku/viewtopic.php?t=394&mforum=sudoku Subsets http://www.setbb.com/sudoku/viewtopic.php?t=231&mforum=sudoku http://www.setbb.com/sudoku/viewtopic.php?t=273&mforum=sudoku X-Wing, Swordfish & Similar patterns http://www.setbb.com/sudoku/viewtopic.php?t=240&mforum=sudoku Fishy Cycles - Turbot Fish - Broken Wing http://www.setbb.com/sudoku/viewtopic.php?t=35&mforum=sudoku http://www.sudoku.com/boards/viewtopic.php?t=2666 Coloring http://www.setbb.com/sudoku/viewtopic.php?t=311&mforum=sudoku http://www.setbb.com/sudoku/viewtopic.php?p=1562&mforum=sudoku#1562 Advanced Coloring (Super,Multi,Ultra) http://www.setbb.com/sudoku/viewtopic.php?t=139&mforum=sudoku http://www.setbb.com/sudoku/viewtopic.php?t=197&mforum=sudoku http://www.setbb.com/sudoku/viewtopic.php?t=77&mforum=sudoku http://www.setbb.com/sudoku/viewtopic.php?p=2575&mforum=sudoku#2575 Templates http://www.setbb.com/sudoku/viewtopic.php?t=241&mforum=sudoku XY-wing , XYZ-Wing http://www.setbb.com/sudoku/viewtopic.php?t=252&mforum=sudoku http://www.sudoku.com/boards/viewtopic.php?t=3152 Uniqueness http://www.setbb.com/sudoku/viewtopic.php?t=255&mforum=sudoku http://www.setbb.com/sudoku/viewtopic.php?t=323&mforum=sudoku http://www.setbb.com/sudoku/viewtopic.php?t=343&mforum=sudoku http://sudoku.com/boards/viewtopic.php?p=12309 BUG http://www.sudoku.com/boards/viewtopic.php?t=2352 BUG Lite http://www.sudoku.com/boards/viewtopic.php?t=3056 ALS - Almost Locked Sets http://www.sudoku.com/boards/viewtopic.php?t=2694 http://www.sudoku.com/boards/viewtopic.php?t=2510 Nice Loops http://www.sudoku.com/boards/viewtopic.php?t=2752 http://www.sudoku.com/boards/viewtopic.php?t=2751 http://www.sudoku.com/boards/viewtopic.php?t=2966 http://www.sudoku.com/boards/viewtopic.php?t=2575 POM - Fillet-O-Fish (Finned Fish) Edit: the first 2 links cover the developments in March 2006 http://www.setbb.com/sudoku/viewtopic.php?t=750 http://www.sudoku.com/boards/viewtopic.php?t=3496 http://www.sudoku.com/boards/viewtopic.php?t=2932 http://www.sudoku.com/boards/viewtopic.php?t=2793 Tabling - Bifurcating Implication Chains http://www.setbb.com/sudoku/viewtopic.php?t=126&mforum=sudoku http://www.setbb.com/sudoku/viewtopic.php?t=300&mforum=sudoku http://www.sudoku.com/boards/viewtopic.php?t=2859 3D Chains -Medusa http://www.setbb.com/sudoku/viewtopic.php?t=327&mforum=sudoku Dancing Links (DLX) Mike Barker's collection of solving techniques at the Players forum http://www.sudoku.com/boards/viewtopic.php?p=21804#21804 If you have additions, just post them and I will update this list - Ruud Last edited by Ruud on Sat Jun 30, 2007 1:40 pm; edited 10 times in total Back to top gaby Joined: 02 Jul 2005 Posts: 120 : Items Posted: Tue Nov 08, 2005 3:42 pm    Post subject: That is absolutely cracking, Ruud. If you don't mind, I'll merge that with my database of solving techniques (when I finally get round to finishing it... _________________ Free daily sudoku - Online puzzle database http://vanhegan.net/sudoku/ Back to top Carcul Joined: 29 Dec 2005 Posts: 50 : Location: Coimbra, Portugal Items Posted: Mon Feb 13, 2006 4:33 pm    Post subject: Hi Ruud. Very good idea. I have just a suggestion: why don't you also add to that list links to topics in the players forum that also cover those techniques or that provide a different view of the techniques? Regards, Carcul Back to top angusj Site Admin Joined: 18 Jun 2005 Posts: 406 : Items Posted: Mon Feb 13, 2006 10:54 pm    Post subject: Where this thread is 'stickied' I think it's important to provide links to simpler techniques too (otherwise newcomers are very likely to give up very quickly). Here are several sites with good explantions of solving techniques which include all of the simpler techniques too: http://angusj.com/sudoku/hints.php http://www.simes.clara.co.uk/programs/sudokutechniques.htm http://www.palmsudoku.com/pages/techniques-overview.php http://www.sudocue.net/guide.php There are quite a number of other good sites but these are the few that came to mind. Please excuse my lack of modesty by including my own site in the above list. Back to top Ruud Site Admin Joined: 17 Sep 2005 Posts: 708 : Location: Netherlands Items Posted: Mon Feb 13, 2006 11:38 pm    Post subject: I included the list in the topic. (Added www to your url) Ruud Back to top Ruud Site Admin Joined: 17 Sep 2005 Posts: 708 : Location: Netherlands Items Posted: Wed Feb 15, 2006 8:42 pm    Post subject: Carcul wrote: why don't you also add to that list links to topics in the players forum that also cover those techniques or that provide a different view of the techniques? I added whatever topics I found useful. Please inform me if you want additional external links or other changes. The players forum is even more difficult to evaluate than this forum. Ruud. _________________ Meet me at sudocue.net Back to top fermat Joined: 05 Feb 2006 Posts: 25 : Location: Melbourne Items Posted: Thu Feb 16, 2006 12:00 am    Post subject: General solving. I think the sticky needs to be two stickies. General, easy help is great. Fairly tough but possible is sorta OK. Utter weird crap....seperate please. I suspect that all single solution puzzles can be solved, the methods have some interest, if done in real time they are good puzzles. Hmmm, real time varies with the solver. The stickie is already longer than I expect people to read. IMHO Back to top angusj Site Admin Joined: 18 Jun 2005 Posts: 406 : Items Posted: Thu Feb 16, 2006 2:33 am    Post subject: Re: General solving. fermat wrote: Utter weird crap....seperate please. I personally find at least two thirds of Ruud's list of techniques too esoteric to be useful and would happily call it "weird crap" too . (I often wonder just how many Sudoku enthusiasts actually use them.) My concern with the list as it stands (especially where it's stickied), is it implies an informal endorsement by this forum of these techniques - something I'm not entirely comfortable with. However, I can also see some merit in having a list like this. Where people can see what techniques have been discovered/documented, it might slow the ever growing list of "new" techniques which turn out to be existing techniques that the "discoverer" was unaware of. (The naming of existing techniques is already confusing beyond reason.) Finally, what some/most consider weird crap, others will consider pure heaven. Back to top Ruud Site Admin Joined: 17 Sep 2005 Posts: 708 : Location: Netherlands Items Posted: Thu Feb 16, 2006 3:15 pm    Post subject: angusj wrote: I personally find at least two thirds of Ruud's list of techniques too esoteric to be useful and would happily call it "weird crap" too. Actually, I found a lot more, but the ones I selected were the techniques that were seriously discussed here and/or on the players forum. The term "weird crap" sounds a little harsh towards these sometimes easy to use and cleverly invented techniques. Many are meant to avoid complicated techniques like forcing chains and multi-colouring, and use pattern recognition instead. With 2/3 of the list nominated for the "weird crap" list, that would also include some of the techniques that are actually built into various solver programs. I'm very curious which "weird crap" techniques I accidentally implemented in my solver... On the other issues: This list does not pretend to be the authorative list of solving techniques. It's just an index. I added it as a service to new forum members. It is very useful to have the index up front and not somewhere in the middle. That is the reason I stickied it. This forum does not have an opinion, so it cannot endorse anything. Each post is the member's vision, and not the forum's, sticky or not. And anyone who does not agree, is free to post a reply. Ruud _________________ Meet me at sudocue.net Back to top angusj Site Admin Joined: 18 Jun 2005 Posts: 406 : Items Posted: Thu Feb 16, 2006 10:03 pm    Post subject: Ruud wrote: The term "weird crap" sounds a little harsh towards these sometimes easy to use and cleverly invented techniques. I was simply borrowing fermat's expression which resonated with me because I personally have found a number of these techniques to be a mixture of hard to understand, rarely useful, renaming of other techniques or presupposing unique solutions. Having said that, all of these techniques are very clever, so I wasn't intending to denigrate any of them. Ruud wrote: With 2/3 of the list nominated for the "weird crap" list, that would also include some of the techniques that are actually built into various solver programs. I'm very curious which "weird crap" techniques I accidentally implemented in my solver... Because I find them "weird" doesn't make them so. Please don't think for one minute I'm trying to impose my opinion on anyone. My opinion is no more or less valid than anyone else's. I don't see it's particularly constructive for me to nominate which I see as "weird" and which I don't. (Since I did mention 'Uniqueness' above, perhaps I'd better clarify my feeling on that. It is a very clever technique which is reasonably simple and seems prevalent enough to be quite useful for difficult puzzles. However, it does require the presupposition that a puzzle has a single solution, something I personally find less than satisfying as to me part of the charm of solving Sudoku is to prove there is just one solution.) Ruud wrote: This list does not pretend to be the authoritative list of solving techniques. It's just an index. I added it as a service to new forum members. It is very useful to have the index up front and not somewhere in the middle. That is the reason I stickied it. I'm really sorry that I've seemed argumentative, that wasn't my intention. I can see now that my comments were more critical than intended. The idea of a stickied list is a very good one, I should have made that clear much earlier, it was simply the 'balance' of the list which concerned me. Ruud wrote: This forum does not have an opinion, so it cannot endorse anything. While that's true, making a thread sticky does imply that a particular thread is more important/helpful. Consequently, since newcomers will target a stickied thread such as this one, I think it's helpful to point out that just about all the techniques in the current list are at the very extreme end of solving techniques. Back to top evert Joined: 30 Aug 2005 Posts: 68 : Location: Amsterdam Items Posted: Tue Feb 21, 2006 8:03 pm    Post subject: I think this explanation for multiple colors is very clear: http://www.setbb.com/phpbb/viewtopic.php?p=2575&mforum=sudoku#2575 Back to top Ruud Site Admin Joined: 17 Sep 2005 Posts: 708 : Location: Netherlands Items Posted: Thu Feb 23, 2006 2:13 am    Post subject: evert wrote: I think this explanation for multiple colors is very clear: http://www.setbb.com/phpbb/viewtopic.php?p=2575&mforum=sudoku#2575 Added to the list. be aware that you're still using the old-style links (phpbb folder, not sudoku) Ruud. Back to top evert Joined: 30 Aug 2005 Posts: 68 : Location: Amsterdam Items Posted: Thu Feb 23, 2006 11:18 am    Post subject: Did I? Probably I found the topic while reading another topic with this old-style link. Many posts still contain the old-style links, could this be converted? Back to top paris Joined: 08 Mar 2006 Posts: 1 : Items Posted: Wed Mar 08, 2006 11:10 pm    Post subject: Hi guys! I am trying to write a program in c which will create and solve sudoku. I am thinking of starting from the "solving" cause I think it's easier... I found those information about the techniques really useful but too much of it! For me i would be very hard to try them all and figure out which is the best. So I am asking you guys to propose me one technique which 1. will solve ANY sudoku and 2. is easy on programming I want to find to find one good algorithm and then start programming. Thanx guys already!! Back to top simz Joined: 16 Mar 2006 Posts: 1 : Location: casa Items Posted: Thu Mar 16, 2006 8:30 pm    Post subject: Sos Sudoku This post has been deleted by a moderator (angusj) because its content is off topic. Also, please post in English. Back to top Display posts from previous: All Posts1 Day7 Days2 Weeks1 Month3 Months6 Months1 Year Oldest FirstNewest First         Sudoku Programmers Forum Index -> Solving sudoku All times are GMT Goto page 1, 2, 3  Next Page 1 of 3   Jump to: Select a forum Sudoku----------------Solving sudokuSetting sudokuProgramming sudokuThe mathematics of sudokuExotic sudoku Library----------------PuzzlesSoftwareSudoku elsewhere Not sudoku----------------Random thoughtsForum feedback  You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum   Powered by phpBB © 2001, 2005 phpBB Group Igloo Theme Version 1.0 :: Created By: Andrew Charron