OAPC 5

[gulce]

But how could you build a hole if the Coral "cannot touch itself, not even diagonally"?
How could you fully surround an empty cell with blackened cells with this rule?

See picture, this is not allowed. We couldn'd decide whether this means touching itself or not , so we wrote holes are forbidden


edit: I looked once more and decided that the wall in the picture is really touching itself After dealing with so many puzzles I've lost my vision to see things easily