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Rules -- The Inner Limits

The Inner Limits was invented by the Japanese puzzle company Nikoli (under the name Bag, although the name Corral is probably more well-known amongst the global puzzle community).

1. Draw a single loop along the grid lines. The loop may not cross itself or branch off. In other words, the interior of the loop will be a single polygon.
2. Every number must be contained inside the loop.
3. A number indicates how many grid cells, including the cell itself, lie in an uninterrupted horizontal or vertical line from that cell, up to the nearest edges of the loop.


Jonah said...

One of my favorite forms. Glad to see it on here!

Magnuscoatl said...

I believe that this can equally be expressed as:

Shade each square black or white (numbered squares are always white)

The number in a square indicates how many squares (including itself)lie in an uninterrupted orthogonal line from that cell, up to the nearest edges of the loop.

All white cells are connected by edges.

All black cells are connected to the border by edges.

Thinking of it this way makes it easier (I find) to solve on the computer.

Grant Fikes said...

Magnuscoatl: That applies to most of my readers, I believe.

Boomer said...

Yes, that's how I solve them too.
As a result, there is one particular situation that I frequently find myself second-guessing that would have been obvious with the original rules. This one:


Jonah said...

It's still obvious if you use the fact that K_4 isn't an outerplanar graph.

Over-thinking it,

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