Posts

WPC 2023: 13th place! And puzzle people are real!

Image
After solving and constructing logic puzzles for three years, I finally decided (and had the opportunity) to go to WPC (the puzzle part of the world sudoku+puzzle championship). It has been a wonderful and thrilling four days, and I aim to recap the incredible experience I had in this post. October 18, 2023 I took a taxi from Billy Bishop airport (with a terrific view of Canada's trees in autumn) to the hotel, and I immediately got to marking my nametag: I found many Puzzlers' club members at a large table. It was my first time meeting them all: djmathman (David Altizio) was super excited to see me, and I was just as excited to see him and everybody else (Kevin Sun, Dan Katz, Thomas Luo, Tim Miller, Yuan Yao, Walker , Victor, and more). My roommate IHNN would arrive later. Tim and Dan were both on the USA B team like me, so I made sure to greet them well. People were practicing castle walls, and I heard tluo considering buying a GMPuzzles subscription for more math path pract

Yajilin (exercise)

Image
During WPC 2023, Craig and bakpao hosted a speed-setting contest in person. The prompt was to make a Yajilin variation. Here's the Yajilin (exercise) I came up with, which won 1st place! It's only slightly cursed. Penpa link:  https://tinyurl.com/ytfydo2d Rules: Shade some cells in the grid so that each arrow (yajilin clue) sees the indicated number of shaded cells. Some shaded cells are given. Shaded cells may be adjacent. Then treat the resulting grid as an Exercise puzzle. That is, draw a directed loop through cells which can push shaded cells into empty cells. A shaded cell can move exactly once in the direction it's pushed, and can only move once. Shaded cells can't push other shaded cells. The finished, traversed loop must pass through all empty cells in the grid. Note: The yajilin clues only care about the shaded cells before they've been pushed by the loop. I've been told the rules are confusing (what a surprise!), so here's an example: Below is th

Cave (diagonal)

Image
Here's another Cave variation, made to practice for WPC 2023. Penpa link:  https://tinyurl.com/yuwzdych Rules: Shade some cells in the grid. The numbers must be unshaded, and tell how many cells it sees diagonally (including itself!). All unshaded cells must be connected. All shaded cells must be connected to the outside of the grid.

Cave (no 2x2)

Image
WPC 2023 had some Cave variations, so I made this in preparation. The no 2x2 constraint is surprisingly finnicky in construction-- perhaps if I knew yin-yang theory, I could have spent less time trying to fix an impossible set of clues. Penpa link:  https://tinyurl.com/ylozmfj4 Rules: Shade some cells in the grid. The numbers must be unshaded, and tell how many cells it sees horizontally/vertically (including itself!). All unshaded cells must be connected. All shaded cells must be connected to the outside of the grid. No 2x2 may be entirely unshaded or entirely shaded.

Akari (Myopia)

Image
Here is an Akari (Myopia) I made to practice for WPC 2023. Penpa link:  https://tinyurl.com/yso8rv23 Rules: Place a light bulb to some of the white cells so that each white cell is lit up. Each light bulb illuminates the cell it is in, as well as any horizontally and vertically adjacent cells, stopping at any black cells. No bulb can illuminate another bulb. Also, the arrow clues indicate all the directions (up, down, left, and right) where the nearest light bulbs are located when looking from that cell. Arrow clues block the light bulbs, but do not block any other arrow clues. No light bulb can be placed in a cell with an arrow.

Statue Park (Myopia)

Image
Here is a Statue Park (Myopia) which I made to practice for WPC 2023. It took many tries to get logic I was satisfied with!  Penpa link:  https://tinyurl.com/ynyv98ro Rules: Place each of the shapes from the bank exactly once into the grid, with rotations/reflections allowed. No two shapes can overlap or be orthogonally adjacent. All unshaded cells must be connected. Also, arrow clues are unshaded, and indicate all the directions (up, down, left, right) where the nearest shaded cells are located.

Ohio Country Road

Image
 Ohio is very powerful. https://puzz.link/p?country/12/16/jp7vd1633018180c0606gdkckcjvnjuvt410a5jag780410280o000141mgmfjmnc20gg3bum-4am35g16h