Puzzle 272 (Double Back) [Minefield]

This is a Double Back puzzle, with a twist. The loop will not visit every cell in this puzzle. Specifically, exactly one cell in each colored region will not be visited by the loop, and it’s up to you to figure out which cells to omit. All others still must be visited exactly once.

Puzzle 272

Puzzle 272

(Click for larger size)

Revisiting another variation that has too much potential to just be used once.

For most types, when I’m repairing a goof in a puzzle, I sometimes have to struggle to keep in a neat, nontrivial part of the logic. If I’m repairing a Double Back, it’s always a struggle to find a fix at all, and I tend to end up with a different, harder solution that employs logic I found specifically to solve the new version.


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8 Responses to “Puzzle 272 (Double Back) [Minefield]”

  1. David Says:

    The ram design is because of the idiots claiming there’s a new star sign, right? Heh. (If not, disregard.)

    • MellowMelon Says:

      This comment is the first I’ve heard of this star sign being news. The first time I saw something point out Ophiuchus should technically be one was over four years ago actually (and they were not really serious), so I find it especially confusing. In any case, I thought of the design as more of a demon than a ram, so it was not the intent.

  2. rob Says:

    For printing grayscale, it’d be great if you could make the grid lines of these puzzles a little thicker/blacker. Can’t comment on the puzzle itself yet.

  3. aclayton Says:

    Woohoo! Finally.. For days, I had this thing open on my desktop with only two regions filled in the upper right, coming back to it occasionally hoping I’d see what I was missing. Not sure if that first hurdle was set really high, or if I just didn’t understand the puzzle yet, but after jumping it I was able to make consistent, enjoyable progress through the rest. 3 or 4 wrong turns, but luckily I was able to Ctrl-Z back to catch my errors, and was embarrassingly excited to reach the finish.. Thanks!

    • MellowMelon Says:

      The comment in the post is referring to that right edge. It is indeed a high hurdle. It’s logically doable, but it requires a lot of small steps, each pretty involved. I was amazed I saved that part at all.

  4. nicke Says:

    Excellent puzzle. I started from the left, convinced myself I had it correct up to two variations then got stuck. So I restarted from the right, made more progress but was dismayed when it contradicted my half-solution from the left. So then abandoned left-hand solution and finally forged westward to the edge. Had a sinking feeling when I saw the last yellow region had only one path. The a quick rethink and eureka! Took about 3 days off and on. Warmest commendations to MellowMan.

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