Slitherlink by Tom Collyer

Slitherlink by Tom Collyer


or solve online (using our beta test of Penpa-Edit tools in edgex mode where left click+drag draws lines and right click marks X’s)

Theme: Uncommon Patterns

Author/Opus: This is the 45th puzzle from our contributing puzzlemaster Tom Collyer.

Rules: Standard Slitherlink rules.

Difficulty: 3.5 stars

Time Standards (highlight to view): Grandmaster = 4:30, Master = 7:30, Expert = 15:00

Solution: PDF; a solution video is also available here.

Note: Follow this link for classic Slitherlink and this link for Slitherlink variations. If you are new to this puzzle type, here are our easiest Slitherlink puzzles to get started on. More Slitherlink puzzles can be found in The Art of Puzzles, Slitherlink and Variations, and our beginner-friendly book Logic Puzzles 101.

  • MountainManZach says:

    Penpa: [EDITED to remove link as no author/linkback present to this page and our own Penpa version now listed.]

  • Nikolai says:

    The theme is spot on, I really hadn’t seen these patterns before. (Or at least I couldn’t remember seeing them.) I particularly liked the Greek cross with the two surrounded by ones in the top middle. Thank you for a nice puzzle!

  • Tom Collyer says:

    MountainManZach: have you asked anyone’s permission to create those links of a puzzle that you have no rights to republish without the appropriate credit?

  • LorenR says:

    I am not MountainManZach but I have studied many OSS licenses.

    It appears to me that the link posted to this comment thread appears nowhere else on the Internet (either the shortened version, as posted here, or the penpa version which encoded the entire puzzle into the URL).

    Therefore, by sharing this link in exactly this one place (i.e. this comment thread), it appears to me that credit to the original puzzle was actually made fairly clear…

    That said, it would be nice if these various interactive puzzle solving sites allowed one to place such credit explicitly. I am fairly sure this issue came up when Thomas floated the idea of providing such links regularly. I am also fairly sure that a green light was given to post such URLs to the comment threads on this site.

    Personally, I use pen and paper to solve but I really wish I could stop wasting paper.

    • Avatar photo drsudoku says:

      I have never explicitly approved having these links added but also have not taken them down. I take it as a sign we need to move quicker on implementing something here if the solvers are trying to help each other out in this way (and I do appreciate what MountainManZach is trying without asking permission).

      We expect to have an update shortly about these tools that will meet my requirement to have the posts routinely contain author, title, and a link back to GMPuzzles/copyright info (this was recently added to a Penpa branch, but is still missing on, so we are likely moving forward with Penpa deployment here).

  • Tom Collyer says:

    Perhaps I am on the overly cautious side of things, but I am becoming increasingly wary about these online solvers. I appreciate that mine is definitely a minority view, but in general I think they take puzzle authors for granted, and that is ultimately a bad thing. In my eyes things would be greatly improved if there was some kind of clear attribution available within the interface explicitly, as you say LorenR.

    Part of my wariness is not least due to the attitudes to some individuals who maintain these tools. When I’ve tried to communicate some issues I’m worried about, the general reaction has been along the lines of (a) “how dare you criticise my perfect baby which I’ve worked ever so hard on and which everyone loves so much”, and then maybe (b) “even if I accept the issues you raise as being potentially problematic, there’s nothing else for it but to trust me. Smiley face smiley face :-)”

    I find those attitudes a little bit polarising, and more inclined to draw my own lines in the sand in a (frankly pitiful) effort to try and shape better practice.

    So a long story short, I suppose I wasn’t particularly aware of a green light being given to share links in the comments here. I will say that these days third parties sharing links to puzzles that the author isn’t particularly comfortable sharing in that way is a bit of a red rag to a bull with me these days (and yes caveats on OSS licenses etc etc).

  • Rajesh Kumar says:

    Very nice puzzle Tom. I learned a few new techniques to solve the Slitherlinks puzzle after solving this puzzle.
    In fact, I could not solve this puzzle without watching the solution video. Very nice puzzle.

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