Author Archives: ruud

SudokuStart

This was a little too tempting. I’ve been checking dozens of possible site names, most of them were already taken. I used those to build my links collection on www.sudokuplaats.nl.

Suddenly I discovered that sudokustart.com and other related names were not claimed yet. With my superior links database, this is the opportunity to create a very popular links site.

So, that will be done. SudokuStart is registered and I will build a dynamic Sudoku links collection that will make the others bow in humility. A very comprehensive search engine will be placed upon it. And a few ads sprinkled here and there, one’s got to eat, yes?

SudoCue2 is in the making

I have decided to give it a final go and put all the things I’ve learned about writing a cool Sudoku program into this new version. It will not be a simple upgrade, but a complete rewrite of the program. A lot of posts about the project’s progress are to be expected, but here is the plan:

  • Program will be rewritten completely in C#
  • Program will be a sudoku framework, that can be expanded by others
  • It supports custom puzzle formats and constraint definitions
  • It supports custom plug-in skins
  • It supports custom plug-in file formats
  • It supports custom plug-in solving techniques, or complete solvers
  • It supports custom plug-in imports and exports (clipboard and web)
  • It supports custom plug-in helper tools (and the 6 we already have)
  • It supports custom plug-in puzzle generators
  • It supports custom plug-in puzzle rating tools
  • The source will be available under GNU2 license.

Is this too ambitious? We’ll see. I’ve contacted the very inactive administrator of the sudoku programmers forum and offered to take over the administration. If that works out OK, then I’ll set up an Open-Source subforum, and this project can be posted there. If not, I will start a new SudoCue2 development forum on the SudoCue.net site. That would be more difficult to plug, but we’ll see…

SudokuPlaats.nl upgrades part 3

I’m not sure why I’m so obsessed with this site. It has such a nice look, and it’s getting better and better. Spent today writing a maintenance interface for the links database.

This is almost a sellable concept. Anyway, I now have some experience in writing maintence pages in PHP. This might come in handy for my next venture, nuf said.

Before we continue, I do want a shout box on SudokuPlaats. So that’s the next challenge.

Uploaded 3 Nightmares.

Looks like Angus is ready to retire. That would leave an opportunity for other freeware programs.

SudokuPlaats.nl has a very nice daily Sudoku interface

OK, I had this coming for quite some time now, but my revision of www.SudokuPlaats.nl is now done. Those poor Dutch could not cope with the daily Nightmares I threw at them at SudoCue.net. It is the chosen few who dare to attack these monsters.

Anyway, the interface allows selection of difficulty, restart, check puzzel and show solution. What more do you need for these ‘easies’?

(update)

And now the navbar has been blinged, and the Links page is eckzdreamley cool, with search dropper, language flags and ratings. It’s all in the database too!

Easies uploaded

I uploaded a few thousand easy sudokus into my site database. They are easy because they only require singles to solve. They are also a heartache because they were selected for slow solving paths. The best one requires 26 rounds of solving. I will put these on my Dutch support site, and report availability to my syndicated sites.

Written a mail to a young sudoku site maker about invalid sudokus. Hope it does not scare him off.

A new top listing for Sudokus has emerged. I submitted sudocue.net and it went straight to the top. Now the pressure to come with the top 9×9 has eased a little. This looks like a good listing.

New developments

Not revealing anything yet, but I have registered 4 domains and they’re beauties.

A new application is in the making. Sorry, it is not Sudoku related.

Also, worked on the Sudoku database. Another 10,000 have been added. I am now saving more indirect properties of the puzzles and it is possible to hunt for special combinations of properties. No freebees, tight solving path, breath in solving techniques, large number of eliminations between single steps.

We can now almost supply a Sudoku “made to order”. That would be the real killer in syndication.

A Quiet Saturday

Spent some time helping a guy insert the syndicated link to www.SudoCue.net. He finally got it built in and now he’s running a daily Sudoku from my database.

More! More!

Also did some research on the easies in my database. Created a program that does some low-end difficulty analysis. I’m not gonna spill all the beans here, but some of the considerations are:

  • How tight is the solving path? Are there multiple routes or just a single path that you need to follow?
  • How many singles can be placed before an elimination technique is called for?

Refinement in difficulty assessment will help me identify better nightmares.

My toughest Sudoku generated

This is the toughest Sudoku in stock, from my own manufacturing plant. Is it really a complicated one? It just depends on what force is applied against it. A few nice loops could break it… maybe.

 My toughest

  Tough is in the eye of the beholder. In this case, Sudo Cue.

inertia software, the ‘independant’ Top 50

I noticed some very strange behaviour in the Sudoku Top 50, the list that we all like to be high in with our Sudoku websites. The site, with a free vote for sudocue.net, is linked with http://www.inertiasoftware.com/top50/index.php?id=157.

They used to reset the counters once a day, around 12:00 GMT. Now the reset at 17:00 GMT, and, strangly enough, a second reset somewhere in the middle of the night, but never at the same time.

This gives the list 2 counting periods, from 17:00 to 03:00 (or something) and from 03:00 to 17:00.

Now here’s what happens. The site www.su-doku.net (the home of Sudoku on the Internet, yeah..) never makes a high score in the 17:00 to 03:00 timeframe, but gradualy finds its way to the top of the list in the 03:00 to 17:00 timeframe. This site happens to be Inertia’s own website, where they demonstrate their online version of Sudoku Quest.

So, what is happening here? How easy would it be for Inertia Software to give their own site a few extra votes from time to time? For me, it would be no problem at all, I can assure you that.

I already disliked the company because they packaged a searchbar with the download of Sudoku Quest, which was installed without asking confirmation (I can get very angry at such behaviour!!!) and I do not trust them and their Top 50.

My own Top 9×9 is almost ready, and I will promote it furiously as the “honest” Sudoku site ranking list.

Darn, I’m writing too much here….

Uploaded 2 more beautiful nightmares, that will help my addicted players through the weekend.

Readers?

Was surprised to see how many people are reading my daily entries here. OK, needed to tidy it up a bit, and translated the most recent posts in English. Blogging is a dangerous activity. Before you know it, everybody is looking over your shoulder.

Finished the Scanning article in www.Sudopedia.org. May need some revisions, but at least it is a consistent story now. Still no cowriters.

I have isolated the 400.000 Sudokus in my Access database that can be classified as ‘easy’. I will run a special program today, that performs a solving speed test on these sudokus. This is something I found out recently. It is not only the requirement of solving techniques, but also the solving speed that determines the difficulty of a sudoku. For the lower grades, this is the most important benchmark. A whole series of sub-grades can be worked out.

But not for me. I have to keep up my reputation, so I will always supply sudokus that are a tad more difficult than the rest of them. This solving speed test will help me pick out the nice ones.