Wednesday, July 6, 2011

Mochinyoro - medium



A nikoli type,and a cousin of nurikabe,mochinyoro is a very interesting puzzle.The constraint on black cells in particular,make it stand out.
Rules:Group the white cells into some rectangles,all connected to each other diagonally.No two orthogonally touching white cells can belong to different rectangles.Every rectangle contains at most one clue,which equals the area of the rectangle.Some rectangles may not contain a clue,which means the area can be any value.Black cells cannot form a rectangle.


10 comments:

  1. Why is the image 1206 pixels wide? That's more than thrice the puzzle's size!

    About as important: the second 2 in the top row has two placements.

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  2. And that's while consistently assuming R2C5 isn't an extra island. Otherwise, it's the 2 at R4C2 that has two positions.

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  3. The second 2 in the top row is actually in C7.I misplaced it when creating the image

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  4. The rules allow white areas with arbitrary sizes,so you can have white areas which do not contain a number.

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  5. I'm glad you fixed the dimensions. And yes, I remembered the possibility of unclued areas. The multiple solutions I found included one in the lower half of the grid, in the same spot among all four.

    But I still see three solutions. Specifically, moving that 2 only eliminated one of the old solutions. If it were changed to a 3 (and optionally moved elsewhere in the resulting rectangle), there would be a unique solution. (I'd give the exact end sequence, but that would be a spoiler and I'm friggin' tired.)

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  6. I would like to see your solutions.

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  7. All right. Here's the entire grid (again, best viewed in fixed-width font):
    ..o..oo...
    o.o.A..oo.
    o..o..o..o
    .oB..o.o.o
    .C.oo..o.o
    ..o..oo..o
    oo.o...o..
    oo..ooo.oo
    ..o.ooo.oo
    .o..ooo...
    If A is black, connectivity forces B. But if A is white, either B or C works.

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  8. Just found a set of rules I trust (though they might be for a different puzzle called Mochikoro): http://mathgrant.blogspot.com/2010/01/rules-block-band.html

    Those rules don't say that black cells can't form a rectangle (by which I assume you mean any complete group of orthogonally adjacent black cells), but they do say no 2x2 block can be all black. And the second rule by itself doesn't make for a unique solution either, but both rules together make for a unique solution with A and C white.

    Incidentally, I just made a puzzle which uses neither of these rules. It'll be on my LJ on Tuesday.

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  9. It's up: http://cyrebjr.livejournal.com/33588.html

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