Monday, 30 May 2022

pzprPT Masyu experiment

I thought I'd try the same thing as the previous post using the pzprRT interface - this time with Masyu.  

UPDATE: I managed to put out 15 puzzles, which seems absolutely insane to me.  I had speculated that the interface might be a bit more fiddly with Masyu, because you can't just type in numbers - however what won through is the fact that you need far fewer clues to get a valid Masyu puzzle.  So there we go, churn out a puzzle in an average of 2 minutes.  Make of that what you will!

Solved in 0'50.  A fairly tricky puzzle in the end, although enabled with a repetition of my favourite diagonal pairs in the corner.

Solved in 0'44.  Mostly smooth, although a couple of tricky deductions.  My initial impressions are this has been a bit more successful than the Slitherlink experiment to come up with puzzles that don't feel too artificial.

Solved in 1'41.  This is the first one I feel like I missed something - maybe too early to say if that points at a computer generated hallmark, although I didn't really like this as much.

Solved in 0'33.  The theme suffered in order to get something unique out, but this was a lovely smooth puzzle to solve.  I might try and rescue this at a later date!

Solved in 1'09.  Solved nicely enough, but with a couple of moments to sit and think.  But these aren't feeling so artificial to me.  I wonder if that's because I'm a reasonably proficient Masyu solver and just get these things quicker than I do with Slitherlink?  Or indeed if there's an upper limit as to how hard you can make Masyu?

Solved in 0'26.  Finally got an anti-symmetric one going, and it's just as good as any other in this style that I've ever written.  Interesting!

Solved in 0'27.  On a roll with anti-symmetry.  This one has a really nice design actually - maybe it compares favourably to most of the others in this style I've ever written.  Hmmm!

Solved in 0'49.  I'm beginning to enjoy these!  This one had a couple of my favourite patterns to get things going.

Solved in 0'36.  Fine again!  A perfectly reasonable puzzle with a don't close the loop early theme.

Solved in 0'35.  Felt like a perfectly good themed puzzle that solved very smoothly to me.

Solved in 1'24.  Admittedly I guessed here - I wasn't expecting a puzzle with a random selection of white pearls to give anything other than something that needed guesswork.

Solved in 0'30.  I guess all-black pearl puzzles are always going to be less interesting.

Solved in 0'52.  This attempt at anti-symmetry didn't quite work out, but a perfectly decent puzzle!

Solved in 0'37.  Another nice solve!

Solved in 0'36 - more antisymmetry and solved well enough.

Sunday, 29 May 2022

pzprRT slitherlink experiment

Perhaps I'll reflect more on this after I finish the experiment - but for the time being I'm going to live-blog a slitherlink puzzle setting process which relies entirely on the hugely impressive pzprRT project.  Let's see how many puzzles I can publish in the next 30 minutes...

UPDATE: The answer is 9 puzzles, which feels like a lot for 30 minutes worth of work.  I have now gone through and solved them all - they are unique and cover a surprising range of difficulty levels.  Some of them are more fun to solve than others!

Here are the puzzles:

Solved in 1'02.  The solve was a bit disjointed solving symmetric parts of the grid, but after that it was surprisingly smooth.  Not the ugliest looking puzzle in the world either.

Solved in 1'59.  A smooth enough start to the puzzle, it got a bit fiddly at the end.  Some interesting topological deductions in play here but it did feel somehow artificial.

Solved in 4'29.  I didn't want to have to guess to solve any of these puzzles, but I ended up doing so here.  There's probably a clever topological argument at play here, but this one definitely feels the most computer generated puzzle so far.

Solved in 3'13.  Again needed to guess to finish things off at the end, so pretty hard.  You can kind of see how I tried to build up a theme, and then compromised it quickly in order to get out the unique solution.  Not amazing either.

Solved in 1'54.  This one I remember trying to set by including a few patterns of clues I'm familiar with.  It kind of works, but not entirely successfully.  Definitely better than the previous two, but still with an undeniable artificial feeling to it.

Solved in 1'36.  This one is largely easy and with a smooth solve, except for a fiddly end which kind of ruins things a bit.  Again you can see how the initial visual theme got watered down a bit.  I suspect it wouldn't take that much work on this to keep the theme stronger and have a more consistent solve.

Solved in 1'20.  Basically a taburega puzzle for those familiar with the reference.  Solves smoothly and with a couple of interesting moments, but always with the sense that the thing is one big gimmick.

Solved in 2'16.  This one felt very computer generated.

Solved in 0'29.  Nice to have an easy one, although that was always going to be the case using patterns like this.  I suppose if I'm honest I'd have to say this one is fairly taburega-like as well.

Wednesday, 16 February 2022

Results: Sudoku Design Competition

Here's what you've all been waiting for dearest reader, the big reveal!

Firstly, in a completely randomly generated order, here are your (mostly) esteemed and highly talented authors.  I will be in touch over the next few days about the best way to send over the prizes.

Entry A - 0403 came courtesy of Yunus Emre Büyükkale
Entry B - 3233 came courtesy of Tom Collyer (yes, that use of the word "mostly" is there for a reason)
Entry C - 4235 came courtesy of Anuraag Sahay
Entry D - 4438 came courtesy of Jiri Hrdina
Entry E - 5308 came courtesy of Sinchai Rungsangrattanakul
Entry F - 5617 came courtesy of Yoshi Baroshi
Entry G - 6071 came courtesy of Kumaresan R
Entry H - 6283 came courtesy of Gareth Moore
Entry I - 7408 came courtesy of Florian Wortmann
Entry J - 7704 came courtesy of tamz29
Entry K - 9133 came courtesy of Sam Cappleman-Lynes
Entry L - 9158 came courtesy of Jack Lance

[I will edit in a link to a permanent page on this blog to showcase the entries in all their glory, as well as update the PDF.  For now the puzzles can be found:]
I have to say that I went to great lengths to draw up entries as soon I received them to anonymise them and leave until after the closing date, so that I had the best chance of not knowing whose puzzle I was solving as I was going through.  The original idea with 3 picks for me was to roughly group into an easy, medium and hard puzzle, but it didn't quite work out that way in the end.  The first three £25 prizes go to:
  • Entry D - Jiri Hrdina
I thought this was a wonderfully smooth-solving easy puzzle, setting up the obvious hidden pairs in boxes 2, 4, 6 and 8.  These boxes together with box 5 then resolve themselves leaving the corners of the puzzle to be mopped up via some more hidden single.  The sort of highly polished easy puzzle I really appreciate!
  • Entry H - Gareth Moore
I thought this puzzle moved away from an easy level in a very pleasing way, nicely setting up a naked triple half-way through the solve; this was definitely something that set this puzzle apart for me.  

But don't just take my word for it, one very experienced sudoku solver thought that:
H - clearly a favourite. It has a nice solving path, not too easy / not ridiculously hard. ... It would be a good puzzle for the WSC finals or something.
  • Entry L - Jack Lance
Last but certainly not least, as soon as I saw entry L I knew I had a winner on my hands.  The symmetry of this puzzle is absolutely stunning with consecutive pairs arranged in Battenberg formation around the grid, attached to another consecutive pair for good measure.  However what I find most pleasing about the symmetry is that it doesn't fall into the pastiched trap of a Gurth's Theorem situation where you only get to solve half (or even a quarter) of a puzzle.  Crucially with this puzzle different given digits in the grid are not rotational symmetric from other given digits, which breaks the symmetry and ensures the puzzle maintains an interesting, albeit easier solve.  Absolutely beautiful - this is the single puzzle from the set that I wish I had written and in my eyes is now *the* definitive puzzle for this layout.  For whatever that is worth :-)

Finally, the last £25 went down to the public vote.  My previous post announced that I would be disregarding votes from the authors themselves, but in the end this made no difference to the overall winner.  Which is:
  • Entry G - Kumaresan R
Interestingly my dearest readers plumped for one of the Extra Hard puzzles, which i think neatly wraps up the set of prizes (I should add I had picked my favourites before I counted the votes - in theory an entry could have one two prizes).  It must be said Extra Hard in this case comes with a bit of a health warning - you can use a uniqueness technique to turn this puzzle into a much smoother solve, however knowing that some solvers prefer not to use uniqueness if they can help it, this was how I felt I had to rate the puzzle.

The author had this to say about the puzzle: 
Actually it is not hard but an advance technique is involved. Without this technique unique rectangle can be used to complete the puzzle.
Whilst another solver said:
The puzzle I preferred requires a very unusual way of uniqueness, which once found solves the puzzle. Not sure for the 10/10 rating for difficulty since it was an easy spot, but surely 10/10 of cleverness!
Narrowly losing out in the public vote (regardless of whether author votes were taken into account or not) were entries H and F.  We've already discussed entry H, but entry F was the other Extra Hard entry from the set, and perhaps demonstrates that there is something of an appetite for more difficult puzzles.

That's it for now - congratulations to all the participants and especially the 4 winners!  I'll probably look to do some more of these fixed layout competitions with other puzzle style in the future, as I think it went down well with both those who submitted a puzzle as well as those who voted on them.  

Tuesday, 15 February 2022

Puzzle design competition: results soon

This will be the penultimate post regarding the puzzle design competition. I have decided my top 3 and will be republishing the puzzles with credit over the next couple of days.  I hope you are all looking forward to finally being able to put names to puzzles!

I had fewer votes (10) than entries (12), which I find very curious - I’d like to hear what factors might have been holding people back, even if it’s just speculation.  To those who did vote, thank you very much for participating and leaving your comments, I am glad that you enjoyed this idea.

Some of the 10 votes were from entrants, which I had assumed wouldn’t really matter given I was expecting far more votes than entries, however before tallying up the votes it seems like the only sensible thing to do is to disregard author votes. I can’t see how an individual vote for oneself would not be significant in these circumstances, and given not every author voted there is clear unfairness here in my eyes. 

Saturday, 12 February 2022

Public vote closes soon

A friendly reminder to all my dearest readers that the public vote for your favourite entries from the puzzle design competition is closing soon - 23:59 GMT on Monday 14th February. 

I don’t have all that many votes right now so it’s be good to change this over the next couple of days to see if we can settle on a clear winner. 

I hope everyone has been enjoying the puzzles so far!

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