Puzzle 362 Penalty Heyawake

It's been a good long while dearest reader, but here's something I came up with on a bit of a whim.  Come to think of it, lots of things about this post are a bit scatter-gun.  For one, Puzzle 361 remains unpublished.  For two I don't know if this means I'll be posting anything other than quick ideas in the near future (not that I suppose I ever posted anything other than relatively quick ideas).

But yes.  All that aside, the idea of this puzzle is to apply the usual rules of Heyawake.  There is one further constraint to add to the mix: you must not be able to draw a loop in the unshaded squares.

The easiest consequence of this is that there cannot be any 2x2 blocks of unshaded squares, but there are a couple more of logical consequences/solving heuristics to consider.  I'm not sure how many of them make it into this puzzle, or whether it's something that is really worth exploring in all that much detail, or even indeed whether this is a particularly helpful name of the variation... but it will have to do for now.  Enjoy!

    #362 Penalty Heyawake – rated 5/10 [Medium]

All puzzles © Tom Collyer 2009-23.

Unofficial Championship Host's Guidebook

Before I get going, a couple of quick note to self: 

1. Move this somewhere more permanent on the blog, and dig up other similar posts!
2. Finish the post!

I don't know exactly how much appetite there is for this kind of post, but I don't think it's of no interest at all.  Hopefully it's of more interest than the existing WPF guidebook that exists somewhere on the internet, but that I am not interested enough in to find and link to right now.

The best approach to this kind of thing is to somehow work backwards from a successful outcome.  To that end, I will draw on my many experiences as a competition participant as well as my experience as a competition organiser to run through all the things a participant tends to experience at a well-run event.

These then can be regrouped from an organiser's point of view.

WSPC 22: Aftermath

So the intention wasn’t to leave the last post as something of a cliffhanger, but it turns out I didn’t really have the energy to do updates during the week. 

The first thing to say is that the week was a bit of a rollercoaster. There were some unpleasant lows I won’t speak more about, but they left me feeling greatly saddened and robbed me of both self-esteem and proper sleep during the week. That’s never ideal when you want to be at peak mental sharpness, to say the least.

But overall it was great to return to things after 3 long years away. The puzzle solving itself also had its ups and downs; that’s usually the case but this year I was well within my usual abilities. I do think the WPC in particular will go down as a classic vintage. The 3 years away has given the opportunity for a new generation of solvers and authors to break through, and it has been a real delight to meet some of them and start new friendships. And of course to meet dear old friends once again.

I’ll be doing some posts with the added benefit of hindsight when I’m back to London. These will probably focus more on the highs as I think it’s about time to put the aforementioned lows behind now. 

WSPC 22: Ouch

I didn’t get around to finish posting yesterday, having been totally drained of all energy: mental, physical, emotional. It seems cruel that insomnia now prevents me from finding rest and peace for the night. 

I don’t know if I’ll keep posting through the rest of the week. To be honest, yesterday hit me pretty hard, as I’m sure anyone reading this is beginning to realise. I really wanted to make a good year of it, and I thought I was supposed to be reasonably good at this stuff, but everything seems to be falling apart and I can’t seem to process any of it. I’m in a pretty low place, feeling helpless and useless and in need of a hug. 

WSPC 22: Day 1

On to the first day of competition at the world sudoku championships. I started the day full of excitement, but perhaps not quite with a level of mental sharpness ready to start the competition. 

We’re up to lunch now and I’m licking my wounds; the morning’s solving counts as one of the more chastening experiences I have had in 15+ years of solving. 

I’ll edit in more later, but for now I am at least comforted by the general consensus in the room that it has been hard! Seriously hard! Hard enough to make me wonder whether having a non-zero round represents a good achievement now. I will be even more studiously avoiding anything looking like scores or a leaderboard from now on. That was always going to be the case, but the readjusting of expectations this morning has hit me hard and left me low and disappointed. 

The first round was classics only, and I think the only way to look at things is an acceptance I choked. I got one puzzle done, tried enough twice, convinced myself there was an unresolvable contradiction and from there on in I was making errors left right and centre. 

The rounds after were disappointing in many ways. The second was looking ok, but ended up spending a lot of time on a puzzle without being able to finish it. Round 3 had a combination of 1 and 2’s woes, wasting a large amount of time on a puzzle I was convinced could not have a solution. Round 4 was just hard all round - no contradictions this time, but also not much in the way of puzzles solved either. I think I might have one. 

The morning ended with round 5, a very large samurai sudoku with 14 overlapping grids. Speaking with others this was also very hard, but I finally managed to get a good round under my belt. I’ll claim 11/14 completed grids in the 30 minutes - which is going to be close to my round 1-4 scores combined if there are no errors. Let’s hope not!

As far as the contenders are going, I don’t really have a feel for things. I had a nice chat with the ever-kind Tiit Vunk about the mental side of long distance running - he’s not feeling the pressure too much this year and is instead focussing on enjoying all the puzzles he’s able to solve. I’m not sure many are finishing rounds, or even close to, but performance of the day goes to Kota Morinishi - he got that Samurai out in what I think was 18 minutes. 14 9x9 grids in 18 minutes! And that’s with what felt like the requirement to place numbers in about 8 of them before you could really get going. I think I heard Tantan declare with roughly 5 to go as well, but I think given how things have gone so far I can imagine Kota being an imperious position at the front of the pack. 

On to the afternoon!