I’ve become totally, helplessly addicted to Sudoku, a Japanese logic puzzle which can be anything from ridiculously easy to fiendishly difficult. The concept is simple: take a nine-by-nine grid of squares and divide it into nine three-by-three squares using bold lines, chuck in a few numbers to start off with and off you go. Each row, each column and each three-by-three block must contain all the digits from one to nine. It sounds simple and it is, with the easy puzzles giving you plenty of information to start you off. The more challenging ones give you fewer numbers to start with and have them carefully arranged to cause maximum headaches.
I’ve been doing the Times’ daily puzzles, which start on Mondays with a nice simple problem and finish on Saturdays with a prize problem, and I’ve also been scouring the net for more in order to feed my growing habit. This thing could eat my life very quickly if I let it.
Re Comment 48: Babs, I don’t know what the Samurai Sudoku was like, but I can give you a rough idea of what you can expect to find in the Japanese magazines (or at least the ones I get). There are standard graded 9x9s and larger grids of various sizes. The biggest I’ve seen is 28×28. Variants to the standard include the numbers 1-9 placed also on both long diagonals and the “latin squares” type, where 1-9 is placed in different shapes. This one also has diagonal placing. There are multiple grids that interlock so that numbers are shared, 3D grids, other assorted variants, a few other logic puzzles, fold-outs of large puzzles and a little pull-out book of additional puzzles. If none of this sounds similar to the Samurai Sudoku, please could you describe it and I’ll see if it comes under the “other assorted variants”!
I believe there are around 10 number place magazines published in Japan and I’m on a quest to find and sample each and every one of them! I know of one English language website so far, Fujisan.com but I don’t think they ship internationally. If I come across another site, I will let you know. You could also try other sources, e.g. Asian bookshops, if there are any in your area, who could import the magazines. I get my magazines from the Japancentre Bookshop in London who do a mail order service. If you wish to contact them the telephone number is 020 7439 8035 (ask for Kato, who manages subscriptions). Email: info@japancentrebookshop.co.uk. Pricewise, the magazines will cost you around ?6 – not that much different from the Times or Telegraph paperbacks, but far better in quantity and variety. The 3 magazines I get range between 150 to over 200 puzzles an issue.
Should you find other websites, you might need ordering codes for the magazines. These are as follows.
Nanpure Fan – 06815
Nanpure Joy – 06861
Nanpure Joy Special (Cho Nanmon Nanpure) – 06862
Good luck in your search.
Does anyone know what is the minimum number of rows, columns and squares you have to check when you’ve completed a Sudoku puzzle, to make sure you’ve got it right? Obviously this is where you haven’t got (or can’t wait for) the printed solution.
I’m starting up a Sudoku fansite webring to link as many Sudoku sites as possible. If you have a Sudoku related website, joining is totally free and easy. To get started, go to: http://t.webring.com/wrman?ring=sudoku&addsite
Has anyone got the answer to the Samurai Sudoku from UK Times 28th May – I missed the answer in Tuesdays Times and am going slowly mad trying to solve it. Thanks
I’ve been solving Sudoku puzzles in Nikoli books and other Japanese magazines on and off for over 10 years.
1) If a number place puzzle isn’t symmetrical, it isn’t a “sudoku”, merely a number place puzzle — or what ever else you want to call it.
2) The solution to a Sudoku can ALWAYS be found using logic alone. The logical steps may be beyond the capabilities of the person trying to solve it. The logical steps may required may be convoluted and difficult to describe in an algorithm and therefore difficult to codify.
3) Though ?trial and error? are NEVER required, no matter how difficult the puzzle is — it is a perfectly legitimate logical tactic. The idea that this isn?t logic flies in the face of — logic. Think of a chess player contemplating her next move. She visualizes one move after the other, evaluating each in turn, eliminating those with bad results. ?If I move here, he can move there, I?ll have to move thusly ? oh, then he?ll take my rook. That?s no good. Let?s try something else.? To describe this as ?mere? trial and error rather than logical thinking is absurd.
Whether you like it or not, you are already using T&E to some degree when using other tactics. You are always looking for ?contradictions? allowing you to eliminate possibilities. Deciding which spot to use what method is a series of hunt and search, trial and errors.
4) If you really have a thing against using T&E — here?s another way to approach it: Say you have a cell that can be one of two numbers. Follow the implications each possibility forces. If you can find another cell that BOTH possibilities force — then you can fill that cell without ever having to find a contradiction — in fact, without knowing yet what number belongs in the first cell. I use this method often on the hardest puzzles. For example, my though processes might be: ?Cell a1 is either 8 or 9. If a1 is 8, then d1 must be 7, from that it follows that d4 is 5, and from that it follows that e4 is 6. On the other hand, if a1 is 9, then a8 is 4, from that it follows that f8 is 7, from that it follows that f4 is 5 and finally e4 is 6. Since both a1=8 and a1=9 implies that e4=6.? I don?t think I could codify this method. It?s beyond my skills to implement it in a piece of software. But it?s the most rewarding tactic when it works. Of course, while doing this, sometimes I?ll stumble upon a contradiction and realize that I can eliminate one line of reasoning.
5) When I hear people complaining that one puzzle or other cannot be solved by logic — what they?re actually saying is they don?t like their puzzles too hard. That?s perfectly fine. Though once in a while I like to work on the hardest possible puzzle, most of the time, I prefer to solve those that are somewhat easier. But I don?t fool myself by blaming the puzzle or puzzle constructor. I know my limits. I cannot solve diagram less crossword puzzles though my wife breezes through them. I *know* it is my limitation, not a defect in the puzzle.
Does anyone know where i can get a copy of the bank holiday sumarai sudoku from the times?
I missed the paper and am kicking myself!!
Paul Erdos (RIP), probably the foremost number theorist of our time, used to pose questions|problems along with money rewards as bounty for the solution. Two important questions for SuDoKu which are similar to his questions are:
1) What is the smallest number of givens which has to be provided in order to guarantee a unique solution?
2) What is the maximum number of givens which can be supplied and still provide multiple solutions?
AFAIK, both are unanswered problems.
Sarah: is this the bank holiday sumarai sudoku you’re talking about?
It’s a scan, but better than nothing.
There’s a hint at the bottom alluding to another one.
Symmetry a requirement?
From what I’ve read (in English), symmetry has been a trait to increase the popularity of sudoku.
I’m willing to take a stab at the Japanese to read the particulars but my translating will be much slower than it used to be from a car accident several years ago.
(there’s nothing like a good concussion to cost one nearly all Japanese and virtually all Chinese. Fortunately, English remains.)
Aha! Thanks, Phil, for the scan of the samurai sudoku. I’ve been curious about that puzzle since it was mentioned in comment 48. Nice to know that it is indeed one of the many configurations found in the Japanese magazines and that it’s getting exposure in the UK. I shall have to get the Times more often, now!
ayeeeeeeeeeeeeees ive got 1 it includes 3 differrent puzzles plus the classic su-doku it includes over 80 good luk finding it
Response to comment 35: Its seem that there are quite a number of of mobile versions of sudoku around; the only one i have seen that gives you unlimited puzzles is at http://www.qgates.com can’t wait to get my hands on it…
🙂
I’ve been hunting around for a mobile version that is not limited to x puzzles. I found a new mobile sudoku here at http://www.qgates.com that seems to operate on a wide range of different handsets, including some of the oldies. It looks great but doesn’t appear to be out just yet. I’ve dropped them an email; thought you guys might like the heads up 🙂
John C.
Has anyone found a printable samurai style worksheet? It’s annoying that the puzzle in the Times won’t quite fit in my scanner.
Here is an interesting website.
sudoku.infoforliving.com
Hi All
Hanrahan Media is currently in Production of a new Sudoku Gameshow with Carol Voderman for Sky One. This show will go out live on Sky One on Friday 1st July. We are currently looking for contestants to make up 9 Teams of 9. If you would like to take part in the show then please contact Dan on 01789 450 182 or email green@hanrahanmedia.com and I will contact you.
Marilyn – Thanks for your answers RE #48. It’s good to know that the configuration is in the Japanese magazines as I really like it. So far it’s only in “The Times” on Saturdays afaik.
Just thought you might like to know that there is a new Sudoku program available for download at http://www.GoldstoneServices.co.uk
The full product includes 10,000 brand new puzzles; puzzle solver; design mode to create your own puzzles; print option – handy for journeys; puzzle checker to see if you have made any obvious mistakes; Auto Notes so you can see candidate numbers for each square at a glance.
The demo version includes 10 sample puzzles of varying degrees of difficulty so that you can try before you buy. The product is priced at ?9.99 which is not bad when you consider that thats for 10,000 puzzles!!!
I developed a ?Sudoku Cracker? application. Just fill the initial cells of any ?Valid? Sudoku puzzle, click the ?Fill? button, and in few seconds the 81-cell matrix will be automatically filled.
Are you interested?
Where can i get the samurai sudoku that was in the times on saturday 11 june because i wrote the puzzle down and have realised that i’ve missed a number out. Thank you James
Stacks of puzzles on these sites for your entertainment. The puzzles can be played on-line or printed out. Sites are Japanese, but that shouldn’t deter the intrepid puzzler!
http://www.oct.zaq.ne.jp/woodside/jsudok/
http://www.takana.info/numberquest/index.htm has some interesting configurations.
http://www.takana.info/numberquest/htm/number_200.htm is a very big Samurai type puzzle.
Does anyone know of a simple (read: free) program that can tell whether a Sudoku puzzle is a true one, i.e. has a single unique solution?
I rather not tear the rest of my hair out until I have proof that I haven’t become the victim of a misprint.
In answer to Kanyons post, the (free) demo version of the Sudoku program from http://www.GoldstoneServices.co.uk includes the feature that you require.
Simply enter design mode, clear the board and enter the givens for a puzzle. Having done so, select Test Puzzle and the program will solve the puzzle (without showing you the answer) and tell you whether it is valid or not.
I’ve had some people from a Japanese TV company interviewing me today and they’ve asked me to ask you if you know of any schools that are using Sudoku in their classes or any old people’s homes/social clubs that are using them to help keep their residents’/members’ minds sharp. If you can help you can email Andrew Foord at andrew@nhk.co.uk or phone him on 020-7393-8107.
I’ve tried to solve the Samurai puzzle in today’s Times (18 June 2005)and failed. I believe that it may be flawed. I have verified that I have correct solutions for the central (9×9)Su Doku & the Su Doku containing the solution cell “B”. However, using the 3×3 grid from the central Su Doku in the Su Doku containing the solution cell “A”, I find the puzzle incorrect (I can’t logically have a 3 in the 3×3 grid containing the solution cell”A”). Comments?
I’m also addicted and in our house it’s a race to see who manages to get the paper first each morning! My mum went on holiday yesterday early and took it with her so I haven’t been able to do my samurai one, could someone email it to me please. If I can’t do a normal Su Doku at breakfast, I take it to school as I’m 15 and my friends and I compare ours!
I’ve also found that a samurai sudoku is impossible, not sure what the date is but i know a few other people who treid and all got stuck on the same thing in the centre grid where you had a conflicting 7 or 8
I’ve written Sudoku and Samurai Sudoku Helpers to show which cells are solvable – there is no ‘cheating’, but these features are available for use, if only to save on hair loss! These and some 1620 Sudoku puzzles I generated are downloadable for free from the link below.
There are some GREAT books on ebay…. There are a lot of programs too but.. I prefer to sit down with pencil and paper than stare at the screen for hours on end.. Super Sudoku is also available which drives me mad but is great to achive..
Another new monthly magazine is out, called Su-Doku Time. It has 120 standard grid puzzles with suggested times to beat, ranging between 10 minutes and 45 minutes, some untimed coffee break quickies and brain melters. The magazine costs ?2.50. There’s also mention of two other magazines coming out, Su-Doku Kids and The Big Su-Doku Puzzle Magazine.
Su Doku made easier at http://www.urbanrim.org.uk/sudoku.htm
Response to comment 49 by Mike. There are a number about the web. Mine’s at
http://www.sudokumate.com/sudokumate.asp
Does anyone know where I can buy a Sudoku program for my Palm Tungsten E? Thanks in advance!
Katrina: there’s a Sudoku puzzle for Palm called SingleNumber which you can get from here.
Please visit our Big Dutch Sudoku site at http://sudoku.jouwpagina.nl
Or our Su Doku Forum: http://xray.messageboard.nl/11712/index.php
im 13 and my mum buys the times every saturday and we have an aruguement about whoose going to do the sudoku puzzle coz we both love doing them
There are a few of the Samurai Sudoku Puzzle here:
http://sudoku.4thewww.com/samurai/
They can be printed out in an easy to use format. The answers are also on the page if you get stuck
Hi,
You might be interested in this link: http://games.groups.yahoo.com/group/Sudokuworld/
Kind regards,
Frank
I am so addicteddddddddddd!!!
A new electronic hand-held game is coming out soon. Here are the details.
http://www.play.com/play247.asp?pa=srmr&page=title&r=GADG&title=688974
On Question #83 These are my #1 and #2 favorite Palm Sudoku programs and my comments on them.
http://www.scss.com.au/family/andrew/pdas/palm/myprogs/sudoku/
http://www.onesir.com/sudoku/
http://www.sudoku.com/forums/viewtopic.php?p=5145#5145
can you solve this for me please ?
http://users.skynet.be/film/sudoku.gif
Is anyone going to deSPAM these messages?
Nahoo: The only comments that are allowed here are ones that I have specifically approved. I don’t mind individuals mentioning software they’ve written as long as they don’t go overboard but there’s nothing here that I’d consider spam. There are some frivolous or stupid comments but I’m quite happy to let people show themselves for what they are if that’s what they want to do.
Re comment 64: There is a printable samurai worksheet available at http://sudoku.top-notch.co.uk (as well as free and premium samurai-type puzzles)
Please help me… I have become adicted to Sudoku. However I do not want to pay for puzzles. Can you tell me where I can download free sudoku puzzles?
how many people love sudoku puzzles? loads obviously!!!! however most of da sites they recomend have to be downloaded whilst you want to be able to print them out simplyand easily! my god if only that were soo easy. And i agree that none of these messages are spam but they can be kinda useful and it’s a free country! And anyway as it’s da summer hols i am very easily amused wid the sodoku puzzles- and i am very easily distracted! And i am only 14 and i bet ya u didnt think so at the begginning! caits x x x x x x
A free to use and distribute SuDoKu program is available by request. When solving puzzles, the program explains how and why. Around 2,500 puzzles are also included.
Hi – we have a free puzzle every day on our site, and instructions on how to include it on your own site if you want.
Feel free to add it to your web page.
http://www.sudokuworks.com/DailyPuzzle.asp
Cheers, Dave
If you like sudoku I recommend you PrintSudoku.com. I has 6 new sudokus every day ready for printing.