Puzzle 144: Easy as ABC (Zehnkampf)

Last weekend I took part in a puzzle decathlon, run by Berni of croco-puzzle. That involved 10 rounds modelled on the athletics decathlon, where the running events mapped to puzzle solving (the hurdles were possible broken puzzles), jumping events mapped to puzzle creation, and throwing events mapped to optimization puzzles. A lot of very original ideas, and overall it worked very well. Puzzles and results are available at logic-masters.de.

One of the construction rounds, the Pole Vault, gave you three tries at constructing a high-scoring Easy as ABC puzzle: Before each attempt, you chose a grid size, then had 15 minutes to extend a partially clued puzzle of that size to a correct puzzle. The score was calculated by subtracting twice the number of added outside clues, five times the number of inside clues and once the number of diagonal adjacencies in the solution from ten times the number of rows/columns. I had a rough start there, but ended up with a pretty good third try, with this 8 by 8 puzzle.

easy-zehnkampf

Rules Place letters A-C into the grid so that each letter occurs once in each row and column. Clues indicate the first letter in the corresponding row or column.

Puzzle set: 24 Hour Puzzle Marathon, 2016 edition

Took me a bit longer this year, but here’s my set for the 24 hours from April. I took a bit of a different approach this year, with four puzzles each of six more or less standard puzzle types. My hope was to make the round a bit more approachable than in previous years, though this may have been taking it a bit far. But I think the round worked out fine in the contest.

Individual puzzles below, or get the whole set in PDF: 2016-24h-rob-puzzles.

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Puzzle 143: Nanro Signpost

Here’s a Nanro Signpost.

nanro-signpost-3

Rules Shade some cells, so that all shaded cells are connected, and such that shaded cells don’t fill any 2×2 square. Clues indicated the number of shaded cells in an area; each area must have at least one shaded cell. Whenever two shaded cells touch across walls, the number of shaded cells within both areas must be different.

Puzzle 142: Statue Park

Here’s a Statue Park puzzle, with a full set of pentominoes. I made this one on the train back from the WPC in Senec, I still plan to post some thoughts on that some time.

In other news, I’ve been writing some puzzle sets for Nibbl (Android, iPhone). It’s an app that works as a solving interface and marketplace for handmade puzzles. See also Rohan’s announcement from earlier this year; the interface has been improved quite a bit since then. If you use my referral code ROBR9402 (or someone else’s), you’ll start with 100 credits, with which you should buy some of my star battle or skyscraper puzzles which came out pretty well.

I won’t stop posting here, though, don’t worry!

statue-park

Rules Place a full set of twelve pentominoes in the grid. Different pentominoes must not touch along an edge; they may touch diagonally. Black circles must be part of pentominoes, white circles must not. All cells that are not part of the pentominoes must be connected by edge.

Puzzle 141: Twin-Detector Sudoku (diagonal)

The WSC 2016 is over. I have a lot of puzzles left to solve, but I’m quite happy with my result (54th in the general ranking, after the 39th official participant, after 89/63 last year). Here’s a puzzle I made to help Martin to prepare to become the King of the Mountains (not sure that helped, considering I didn’t quite have the rules right). Test-solved by the new world champion Tiit Vunk of Estonia. Congratulations to both!

twin-detector

Rules Fill the cells with numbers 1 to 9, so that no number repeats in a row, column or outlined 3×3 square. Whenever a number is equal to the sum of some numbers in a diagonal direction, an arrow is placed pointing there.

(The standard rules also have arrows pointing horizontally and vertically.)

Puzzles 138-140: Not Oasis

I played around with what I thought were the rules to Oasis today, and came up with this variant.

Rules Shade some cells, to leave a connected area of unshaded cells that includes all given numbers and doesn’t cover any 2×2 square. Some shaded cells are given. Numbers indicate how many other numbers can be reached through unshaded, unnumbered cells.

Example (a poor example: shaded cells can be adjacent)notoasis-example

Puzzlesnotoasis-1 notoasis-2 notoasis-3

Puzzle 137: Lamps

Just a tiny puzzle that I made as an example for the croco WPC preparation series. It was a bit too hard as an example; the type seems inherently hard.

lamps-small

Rules Place some lamps in the empty cells around the grid, with brightness 0 to 3. The lamps shine horizontally, vertically and diagonally in eight directions. In each direction, they illuminate as many cells as they are bright. Numbers inside the grid indicate how many lamps illuminate the corresponding cell.

The WPC instruction booklet has an example.