Tag Archives: slitherlink

Puzzle 203: Slitherlink [just one segment]

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It’s always fun to figure out some new arguments in a puzzle type. While going through @taburega’s tough puzzles, I ran into one occurrence of a pattern I didn’t know before, and recently managed to distill it into something a bit more memorable while finding some similar arguments in a kwontomloop.com puzzle.

I’m curious how well known these techniques are, let me know! I hope to follow this up with a discussion of the “theory” at some point.

[puzz.link]

Rules This is a Slitherlink puzzles with many solutions, all of which share one segment. Find that segment.

Puzzles 186-188: Standard / Touching Slitherlink

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Here are a couple of puzzles of widely varying difficulty that I made for the hybrid type Standard / Touching Slitherlink that featured in Round 8 (Twilight) of WPC 2019. I could have sworn this variant existed somewhere on the Rätselportal or in the Logic Masters archives, but I couldn’t find it. It’s quite similar in some ways to related hybrids like “Außen-Knapp-daneben-Rundweg”, but has some quite novel features.

Edit Added a clue to the 3s-puzzle to save the intended break-in.

Rules Draw a loop by connecting grid points as in standard Slitherlink. Clues inside the loop act as standard Slitherlink clues (i.e., they count adjacent edges that are used by the loop). Clues outside the loop count how often the loop visits the boundary of the cell, as in Berührungsrundweg (e.g., a clue 4 means that the loop uses all of the cells corners but none of the sides).
Or see the instruction booklet.

[puzz.link without answer check]

[puzz.link without answer check]

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Puzzle 174: Slitherlink (Unequal Lengths), and Russian GP recap

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This past weekend, the WPF hosted round 4 of the 2019 Puzzle Grand Prix, with puzzles by Russian authors. Puzzles/solutions/results are currently available under the previous link but should show up in the archive eventually. I’ll go over how it went for me below. One very interesting new variant on the test was “unequal lengths slitherlink”; here’s one:

Unequal-lengths slitherlink

[applet without answer check]

Rules Solve as a regular slitherlink. In addition, any two connected straight line segments must have different lengths.

Continue reading →

Puzzle 126: Yin-Yang Fences

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And quickly another post to hide that terrible Domino Construction. In contrast, this one has a nice solving path, but will you find it?

yinyang-fences-2

Rules Solve as a standard Slither Link. In addition, all cells outside the loop must be connected, and there must be no 2×2-square of cells that is entirely inside or outside the loop.

Or see the instruction booklet.

Puzzle 121: Yin-Yang Fences

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The next GP round is coming up, with the Russian GP authored by Andrey Bogdanov. One of the types is Yin-Yang Fences, which I first saw on Andrey and Vladimir’s round for the Budapest 24 hours this year. You should be able to find these here. Berni made another for our croco 24h review series.

You can leave out one of the 2s on the outside if you want more of a challenge.

yinyang-fences-1

Rules Solve as a standard Slither Link. In addition, all cells outside the loop must be connected, and there must be no 2×2-square of cells that is entirely inside or outside the loop.

Or see the instruction booklet.

Puzzle 103: Keller, Fences+Dominoes

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Next Keller puzzle. Some of the logic may have been lost in completing the domino part for this one. I find the restrictions that the compatible domino tiling imposes on the loop to be quite interesting in this type, the interaction with the domino puzzle as such less so.

rundweg-domino-keller

Rules The left grid is a domino dissection puzzle. Divide the grid into 2×1-areas such that each domino occurs exactly once. The right grid is a standard fences/slitherlink.

The grids interact: Superimposed over the solved domino grid, the fence can’t bisect a domino.

Puzzle 96: Ecken- und Kantenrundweg

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As a bit of a breather before posting more JaTaHoKus, here’s a puzzle for one of the new types, at least I hadn’t seen it before. It was on the mixed round of the Logic Masters. It’s an “edge and corner fences”.

eckenundkanten

Rules Draw a single loop consisting of vertical and horizontal segments between dots that does not touch or cross itself. Clue numbers indicate the number of adjacent edges and corners that are used by the loop.

Puzzle 53: Slitherlink außen-knapp-daneben

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Here’s a practice puzzle for the other non-standard type on the Serbian GP this weekend, “Slitherlink Out-Liars” as they call it. I’m not too sure this one is representative of the type; certainly it feels different than the others I’ve solved.

rundweg-aussen-kdRules Draw a single loop that doesn’t touch or cross itself by connecting dots horizontally and vertically. Clues inside the loop indicate the number of adjacent edges used by the loop. Clues outside the loop indicate the number of adjacent edges used by the loop, plus or minus 1. Or see the instruction booklet.

Some more puzzles: 2010 German qualification. On croco puzzle: 2013-12-21, 2014-02-08, 2014-04-26. There was also one in the 2014 WPC.

Puzzle 25: Slitherlink (Liar Diagonal)

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Here’s a slightly different take on the Liar Diagonal Slitherlink.

slither-liar-diagonal-gaps

Rules Draw a loop that travels horizontally, vertically or diagonally from point to point. Clue numbers that are not crossed by diagonals are equal to the number of adjacent horizontal and vertical segments used by the loop. Those that are crossed by diagonals are different from that number. Furthermore, in every row and column, there is exactly one diagonal segment, and that  diagonal crosses a clue.