Puzzles #453, #454 & #455 - IPC 2022 Round 3 (Kakuro, Yajilin)

I was fortunate enough to be offered the opportunity to contribute to and testsolve for the 2022 Indian Puzzle Championship. The third round was for puzzle types that appeared in the LMI Daily Contest series, and I made a Kakuro and two Yajilin worth 50, 25 and 40 points, respectively.

puzz.link interface

I started by toying with a layout until I found one I liked that would support every clue with 2 directions having the same value in both directions. At the end of the puzzle, I was fortunate enough to allow having two unclued lines that intersected, which is always a neat thing to have happen.

puzz.link interface

puzz.link interface

As for these two Yajilin puzzles? Both ended up giving me a lot of trouble to end up working out the way I wanted them to. The IPC puzzle was aesthetically challenging to balance while the logic mostly did what I wanted (though I didn't want to include a 4, I liked what it did enough to keep it). The 2022 puzzle on the other hand was excruciating to get a puzzle that worked at all, even though the aesthetic balance was easy to get something nice for. I think this was the 3rd or 4th working puzzle I turned up and it was by far the best one. All of these are puzzles I'm really happy with and I'd gladly contribute to a contest like this again in the future.

Puzzles #366, #367 & #368 - Hexagony Kakuro

Hexagony needed number placement genres, and the usual latin square genres wouldn't make the jump effectively. The obvious solution was to pick a genre that didn't really care about representing every number in its set, and that was Kakuro. I haven't made too many of these but knew I was up to the task as I've solved a ton and know a lot of cool tricks that sometimes come up. Even still, the hexagonal one was the first puzzle made for Hexagony as I knew that hexagonal number placement would prove to be one of the biggest challenges to get into a good place.

puzz.link interface

I'm actually quite happy with how this example turned out, as it shows everything I wanted to show. Some rows aren't clued at all, large and small restricted sums are used, and min-maxing intersections is important as well. It's not the full Kakuro toolkit, not even close, but it does the job.

puzz.link interface

Much later, I went to fill in some of the missing gaps in construction with the necessary difficulties. An easier puzzle was needed, and so I made this "Plus or Minus" puzzle, which solves in two halves. The bottom is mostly straightforward, while the top is quite tough without a critical insight.

penpa interface

I really wanted to sneak in some triangular min-maxing here, but the addition never quite worked out in the end. Despite only having 13 more cells (33%) more than the first Kakuro in the contest, this was worth 45 points- 3 times as much! Some of the required chaining is hard to spot, and there are a lot more sums that are only used to fill one cell after another is resolved. This one is a bit rough around the edges and could have been better- I'll probably revisit the type some time down the road.

Puzzle #275 - In Absentia (Kakuro/Kropki)

Kakuro is kind of bland. Kropki isn't, in my opinion. Adding the dots and negative constraint to Kakuro proved to be a wonderful experience for construction- dead ends were immediately obvious, there were tons of highly restricted cells to work with and influence in many ways, and I even got to avoid cluing a bunch of cells directly.

puzz.link interface

Oh, did I say I added dots? What happened to them 🙄

That's right, all dots are given. All 0 of them. Have fun, and happy holidays!

Puzzle #173 - Thirty Nine (Kakuro)

For how common of a genre Kakuro is I've never had a real desire to try making one until very recently, while thinking about highly constrained sums. 39 is highly constrained in 6, 7 and 8 cell groups, so... I had to try utilizing that. It was a bit of a headache to try to keep some of the logic I discovered intact, and hopefully it survived into the final puzzle.

puzz.link interface

update to fix uniqueness in the lower left (thanks rob!)