Sudoku Pro issue 50 digital version still online

If you were a subscriber to Sudoku Pro then you can still get hold of issue 50, which so far as I know wasn’t received through the post (but I could be wrong).

Anyway, using Google’s page cache I’ve retrieved the previously-published URL:

http://viewer.zmags.com/auth.php?magid=210247

Note that to use this you will need your subscriber number, which was on the bit of paper with your delivery address. Enter that in the top box, and your surname in the bottom box.

It’s still working as of right now, at any rate.

And here’s the previous issue 49, also thanks to Google: http://viewer.zmags.com/auth.php?magid=198026

I can’t imagine these will keep working too much longer, but who knows?

Toroidal Calcudoku


Toroidal Calcudoku puzzle

Another easy Calcudoku in terms of its logic, although this one is a little trickier in practice since it’s 7×7 and is toroidal, meaning that some of the regions wrap around the edges of the grid and continue on the square directly opposite on that row/column.  Other than, just place 1 to 7 in each row and column whilst fulfilling the mathematical results given for each region. Unlike Killer Sudoku, you can repeat a digit within a cage (although of course not a row or column).

Sudoku Xtra – a brand new magazine


Sudoku Xtra – The Magazine for Japanese Puzzle Fans

Today someone commented on my blog here about how Sudoku Pro subscribers who get in touch about their magazines are being told that Accolade Puzzles Ltd, the publisher, is no more, so I thought I should comment.

As a freelance puzzle author I get commissioned by a wide range of different publishers, and I don’t work (and never have worked) for Accolade Puzzles, the publishers of Sudoku Pro magazine, so I don’t know any of the gory details. What I do know is that sadly Accolade Puzzles have ceased trading and entered formal insolvency. I also see today that all mention of them is gone from their parent site, Accolade Publishing, and that the Total Puzzles brand site which covered all of their magazines now redirects visitors to the appointed insolvency practitioners

This is very sad news for me, because I always thought of Sudoku Pro as ‘my’ magazine – I wrote literally all of the content for it, from the front cover to the back cover, and not just that but all the little things too such as the puzzles instructions, hints and tips for the puzzle of the month and so on.  Every 4 weeks I sent all of the content off to the publisher and I always enjoyed receiving the magazine in the post, and trying out many of my puzzles anew.

It wasn’t marketing hype when the magazine claimed that the puzzles were hand-made – every single puzzle in the magazine was either entirely hand-made or had a significant manual component. None of it was churned out of an off-the-shelf Sudoku generator, unlike (it will hardly surprise you to know) just about every other Sudoku magazine you can buy. (My top tip for Sudoku puzzles is only to buy content with a named author on it!)  If you’re going to play puzzles created with a free generator someone found on the internet, you may as well print them yourself rather than pay someone else for the privilege. Sudoku Pro was never like that, and indeed the final issues had very few regular Sudoku puzzles in them at all – the majority were variants or other Japanese puzzles.

The final issue, number 50, was available digitally online, so for those who didn’t receive a printed copy you could try checking at the digital version site, if you had it bookmarked (I didn’t, so I can’t tell you what the URL was).  I’m afraid I’ve no idea if any printed copies were ever sent out, but I have a PDF I downloaded from the subscriber’s website just last week so I have a copy of issue 50 myself at least. I’d also sent all of the content for issue 51.

I suppose if the magazine was to end then issue 50 was a good number to reach. Of course I suppose it’s always possible that someone will buy up the assets and continue publishing the magazines, but I have literally no idea how likely that is. I thought their titles were way above the average puzzle mush on the market, and they certainly didn’t deserve to go under.

But this now leaves me with a big magazine gap in my life, and so on to my new project: Sudoku Xtra.

I’ve decided to start publishing a monthly puzzle magazine myself, initially along the lines of Sudoku Pro but then hopefully branching out to a wider range of logic and number puzzle content, and with even more variety.  I’m also hoping to encourage other puzzle authors to contribute.  The magazine won’t be essentially just a UK publication like Sudoku Pro but will be available worldwide for download from a website which  I’m in the process of setting up, and also in a printed version from Amazon.com. The printed version will cost $9.99, to cover the on-demand printing cost, but the download version will most likely be just $4.99. In UK pounds that’s about £2.99, which is pretty much what Sudoku Pro cost. It will be formatted in large page format, at 8″ x 10″, so Amazon-delivered copies will be much larger than book size, and it will  nicely fill the page size for both worldwide (A4) and US (Letter) printers.  If it is successful enough then I will also make it available for order in printed form from Amazon.co.uk and many other sites (an up-front cost I am avoiding until I know I can cover it!). At least to start with it will be entirely black and white, so anyone can print it without trouble.

If you’re a puzzle author and would like to contribute, please get in touch. Initially any money made will go to cover costs so I can’t offer any payment for content other than a free PDF copy, but hopefully I’ll be able to grow the magazine both in terms of readership and content and it will be a worthwhile thing to contribute to and indeed receive. And then going forward, who knows?

Also if this is something you’d be interested in buying then please post here too with any comments, including what sort of puzzles you’d like to see and how many puzzles you’d expect in the magazine (Sudoku Pro had 67 puzzles, plus the four brain workouts on the back page). I am assuming that a monthly (12 issues/year) format would be best, although without any distributor schedule to keep to this could be flexible and shift around slightly.

Perhaps the (probable) end of one magazine can also signal the beginning of something new?

Just a couple of Calcudoku


Calcudoku 2 puzz

Calcudoku 1 puzz

Today I was producing a few easy Calcudoku for a new book I’m working on, and had some left over so I thought I’d post them here. Nothing too special, but there’s a little bit of nice symmetry, which you don’t seem to generally find in published Calcudoku puzzles. (I don’t know why this is, since it only makes the puzzles better in my opinion!)

See older Calcudoku posts for the rules, if you need them (click the link in the side bar).

Jigsaw Sudoku


Sudoku Jigsaw Medium puzzle

I’m adding features back in to my new puzzle assistant front end code so today I thought I’d post the standard Jigsaw Sudoku puzzle that was my test subject – just fit 1-9 into each row, column and bold-lined shape.

Just a Sudoku


Sudoku easy puzzle

I haven’t posted here for a while, but it doesn’t mean I haven’t been working on various puzzle projects.  One of the things I have been doing is upgrading my puzzle assistant code to be easier to use and more integrated than ever before, and the first part of testing this is to make a plain and simple vanilla Sudoku.  So here it is.  It’s very easy.

Meanwhile, the recent US Sudoku Championship hit the news not just for its $25,000 (£15,000) prize pot but also because it seems one of the three advanced level finalists cheated to get to the final (and win $3,000 / £1,800), possibly because the organisers seem to have allowed people to have all sorts of electronic devices with them whilst solving.  The cheques have been held whilst they work out what happened.

Sudoku Pro Digital Edition

If you’re a subscriber to Sudoku Pro magazine (the best “Japanese puzzle” magazine anywhere outside Japan – although I do write every puzzle in it so perhaps I have some bias; but it really is good) then there’s now a digital edition included free with every printed copy. You can go online with the code printed on your delivery notice and view and print the puzzles out as many times as you like, until, perhaps, you finally solve them! :)
Sudoku Pro online

The latest issue is number 49, and the puzzles in it include:

  • Hanjie
  • Killer Sudoku (and Killer Sudoku X)
  • Jigsaw Sudoku (both 6×6 and 9×9)
  • Sudoku X
  • Toroidal Sudoku
  • Futoshiki
  • Nurikabe
  • Masyu
  • Yajilin
  • Hitori
  • Dominoes
  • Sudoku Inequality
  • Battleships
  • Hashi
  • Kakuro
  • CalcuDoku
  • Consecutive Sudoku
  • Sudoku Extra Regions
  • Samurai Sudoku
  • Samurai Star (Sudoku)
  • Slitherlink
  • Jigsaw Killer Sudoku
  • and of course Sudoku (including 6×6, 9×9, 12×12, 16×16 and 25×25)

Plus each issue has a guest ‘master class’ puzzle – issue 49’s guest puzzle is Number link.  And there’s also the Mind Gym at the back, which this month features various memory tests.

There’s more details and some sample pages on the Total Puzzles website.

PS Sorry I haven’t posted for a while – I’ve had various distractions, both work and family, over the past month, but as of tomorrow hopefully things are going to return to relative normality!

Solving Sudoku using Robots!

Sudoku Solver robot

Sudoku Solver robot

Not a puzzle in itself, but I came across something related to Sudoku that’s so technically impressive that I just had to post about it.

There are plenty of online or interactive Sudoku solvers, and even some real-world ones which take the pages of a book, scan it in and then solve.  SudokuGrab for iPod/iPhone is one popular example, whilst other people have used a combination of Lego and a webcam to scan in and solve entire books.

But how about this?  A Sudoku solver robot which you can build yourself, and doesn’t even need a computer to drive it – it runs directly from a single Mindstorms Lego robotics kit.  It’s unbelievable to watch it work, using a single point light sensor which the robot waves back and forth over the paper to build an image – there is no Lego webcam which can be integrated with the Mindstorms robotic kit.  And then, as if it wasn’t already impressive enough, it uses a real pen to write in the solution.

It’s just amazing – take a look at the robot!

4-Lane Bridges (4-line Hashi)


Hashi 4-way puzzle

I’ve been on holiday, so sorry for the lack of posts.  But, very quickly, here’s a 4-way Hashi for you! :)  Connect no more than 4 bridges between any pair of horizontally or vertically neighbouring islands.

Good luck! :)

Hashi variation – 3-lines


Hashi-3 12×12 puzzle

Hashi-3 example solution

I’ve been discussing Hashi variations in the comments to a previous posting, so I thought I’d try out one of them today.  This is not a brand new variation because it’s a somewhat obvious change, but it’s not very commonly seen even so.

In this version of Hashi you must place no more than 3 lines between any two islands (as opposed to the restriction to no more than 2 lines in regular Hashi).  The full rules, then, are:

  • Each circle represents an island.  You must draw bridges between islands to connect all of the islands together, so you can travel from any given island to any other island just by crossing bridges.
  • Bridges can only be placed in exactly horizontal or vertical directions
  • Bridges cannot cross over any islands – when they reach an island they must stop
  • Each island must have the number of bridges connected to it specified by the number on the island
  • There can be no more than 3 direct bridges between any 2 islands.

Take a look at the example puzzle, which shows how Hashi-3 (anyone got a suggestion for a better name?!) works.

This puzzle is difficult – it will probably take  you a good 15 minutes, despite its size – but see how you find it! :)