The first puzzle I made was a Norinori where the unshaded cells had to be solved as a Double Back. In other words, draw a loop passing through all but 2 cells in every region, that enters and exits every region exactly twice. Cells unused by the loop should be shaded, and each shaded cell should have exactly 1 shaded neighbor. I had a lot of trouble finessing some parts of this to be unique near the end, which was a bit annoying given how nicely the start worked out.
The second puzzle I made was an Aquapelago where each region has to have exactly two unshaded components. Originally I dabbled with a fully clueless grid for this but decided a few clues would be an important addition. The first version of this puzzle was also broken, unfortunately, but I was able to fix it.
Finally, I knew I wanted to make a proper loop puzzle - not just a Yajilin-style mashup. So I combined Double Back with All or Nothing - solve as an All or Nothing where every region is visited either 0 or 2 times.
The first norinori variant. I tried but I did way too much guessing and backtracking so I gave up. I'm not sure what the right approach would be (I tried starting in the bottom right corner, maybe I chose wrong location)
ReplyDeleteUnfortunately, I had the same experience as Negreb with the norinori variant. Would love to know what the intended approach is, since I assume extensive T&E wasn't intended.
ReplyDeleteThe key is the large diagonal regions and parity. If you treat the region as checkerboard colored, there's a surplus of 4 cells of one color. Each loop visit can at most offset 1 of those cells (since the loop alternates colors), and shading a cell also offsets parity by 1. Since you need to offset by 4, and have exactly 4 offsets available, you can then say both that all entries to those regions are on the surplus parity AND all shaded cells are on the surplus parity. Doing this on the bottom large region gives you input into the bottom right smoothly.
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