Puzzle Design Competition - Anonymised Entries

I am pleased to announce there were a total of 12 entries to the Sudoku Fixed Layout Design Competition.  Thank you very much to everyone who submitted an entry, I am honoured that each of you took the time to participate and I am super excited to get solving and judging what I am sure are going to be a truly extraordinary set of puzzles!

I am in a bit of a rush at the time of the initial post - expect this post to updated, probably with a PDF attachment for your printing convenience.  Please note that I haven't asked the authors whether they are happy to provide links to online solving tools, so please take this into consideration before transposing the puzzles and sharing.

UPDATE: difficulty ratings have been added to the post below, and I have also put together a PDF file.  Please note the difficulty ratings are based on my initial solves - a sample of 1 is not usually great for the purposes of testing so do take these with a pinch of a salt.  It is fair to say that the two entries rated at 10 / 10 are significantly more difficult than the rest of the set however!

PDF of entries

Expect a further post in the next couple of days with the voting form and corresponding deadline (which will be in at least a week's time), but in the meantime I thought all my dearest readers would be very keen to get solving as well.

Entries have been anonymised using four random digits as a reference.  I will further update this page with a rough indication of difficult a bit later; for now I will add that, based on the authors' self-assessments, the difficult levels within the collection range from easy through to very difficult.

The last thing to say is that I have run these puzzles through a computer checker to verify they solve uniquely only *after* I have redrawn into a standard format, so this should mean that there are no transposition errors below.  If not, please let me know in the comments.

Update - Puzzle Design Competition

This is a quick update on the previous post.  I haven't really given much thought to how the public vote is going to work, so I've decided to keep it simple.

All the entries will be anonymised and published after the closing date of 31st January, and I will set up a new google form for you to pick your own top 3.  First preference will be awarded 5 points, second preference 3 points and third preference 1 point.  I'll then tot everything up and the entry with the most points will be the public winner.

I'll tentatively say that I'll keep the vote open for about a week after I publish the anonymised submissions.  it really depends on the number of submissions as I'd like to give everyone a reasonable amount of time to solve the puzzles and come to an informed decision about their favourites.

After the public vote I'll publish all the entries with full credit, and contact the winners for the best way to send across the prize money.

That's all for now, I'm really looking forward to solving all these great entries.  Thanks to everyone who has submitted so far.

New Year Puzzle Design Competition

Somewhat on a whim, dearest reader, I have decided to try and revive one of the lesser known institutions of nikoli.com.  The idea was to gather together as many authors as possible to see what they could collectively achieve when they are additionally constrained by a fixed layout of givens.

I'd like to think this would work as an idea all by itself, but by means of encouragement I am willing to offer cash prizes of £25 to my three favourites.  An additional prize of £25 is offered to the winner of a public vote.  I will be accepting entries until the 31st January.

The Puzzle and the Layout:

For this competition, I have chosen Sudoku, without any extra rules, constraints or other variations.  The layout of givens I would like you to follow is this one:

This layout is close to my heart, being very similar to the first ever puzzle I published on this blog back in 2009.  Back then I couldn't quite get this working without having to add an extra given digit at R5C5, but I'm sure my dearest readers will be able to manage without that.  

As an example, I made a small nod to this in one puzzle I made for the 2014 World Sudoku Championships.  This puzzle was additionally designed so that there was no given 9 in the grid.

Submitting your Entry:

This should work via the following google form: https://forms.gle/dZL7XN3GwJWGPEcS6

Please let me know if this isn't working for you.  I think it requires you to be signed in to Google to work, and you will need to attach your entry in a PDF or Image format.

The form should additionally allow you to edit your entry after submitting if you think you can do better, although please note that it will only accept one submission.

Rules:

• No more than one entry per person.
• Collaborations between two or more people are permitted (However you will have to determine how to share any prizes).
• Each entry must be:
• A uniquely solvable puzzle under sudoku rules (no extra constraints or grid decorations permitted).
• Have given digits as per the given layout.
• Not totally computer generated (some computer assistance is fine).
• The last date I will accept entries is 23:59 GMT on Monday 31st January 2022.
• By submitting an entry, you retain full author's copyright, but agree to let me redraw your entry and publish it (with credit to you) on my blog.
• Entries must not be shared or discussed with other entrants before the winners have been declared.

I reserve the right to disqualify entrants and entries not conforming to these rules.  My decisions are final.

Prizes:

• This will kind of depend on how well I've chosen the layout, and the entries received.
• The overall prize pool is £100.  This will include £25 each for my three favourite entries, and a further £25 for the public vote.
• I am happy to send prizes internationally using services such as Wise - although please note that prizes will also need to cover any associated charges and fees.
• You do not have to claim the prize if you do not want to.

Voting:

After the closing date I will anonymously draw up the entries for your solving pleasure.  I am not sure how many entries I will get so I won't commit to a publishing date.  However, after the entries have been published there will be a 7 day voting period.  I will have a think about exactly how I want the voting system to work, but it is likely to involve individuals picking their top 3, and me somehow aggregating this information all together!

Any attempts to manipulate the voting will result in disqualification for the public vote prize.

Puzzle 360: Killer Sudoku

I'm sure this sort of thing must have been tried before, dearest reader.  Not my most elegant work, but the vast majority of the windows will need to be opened if you want to make it through to the end.  Enjoy!

    #360 Killer Sudoku – rated 6/10 [Hard]

All puzzles © Tom Collyer 2009-21.

Puzzle 359: Heyawake

It's been a long time since I did Heyawake.  As with the recent Masyu, it's not entirely Nikoli smooth, and there are bits I'd even go so far as describing as fiddly, but hopefully it makes for a decent challenge at least.

As a bit of an aside, I came across semiexp.net recently, and lots of it basically seems like magic to me.  For example:

• A Numberlink Generator
• (Surprisingly good) Computer generated Slitherlink

There's also something called pzprRT, which seems like an extraordinary setting tool.  Basically, for a small number of types, including 4 of my favourites: Yajilin, Masyu, Slitherlink and indeed Heyawake, you are able to mark up your puzzle using the pzprjs project (i.e. as featured on puzz.link) and then you can press a button and it will give you the live deductions corresponding to the clues you've put in.

I am still generally avoiding marking up my puzzles using puzz.link, as the interaction between the puzzle player and the hidden database (which stores the metadata of logged in solvers) is still not entirely clear to me.  I think I saw that this metadata is indexed by hashed versions of the puzzle URLs rather than the URLs themselves - this would kind of be fine by me I think as it means the database would be genuinely only metadata, rather than actual puzzle data making up some kind of secret dystopian mega master puzzle database.  But in any case pzprRT generated me a puzz.link, so I think it means this puzzle is now on the database, hashed or otherwise, and now what’s done is done.

I suppose what it does mean for you, dearest reader, is that you can also play along online!  I may even start making a habit of it.  Enjoy!

    #359 Heyawake – rated 8/10 [Very Hard]

All puzzles © Tom Collyer 2009-21.