Nurimisaki

Nurimisaki (from Japanese, literally "paint a cape") is a logic puzzle invented by Nikoli. A rectangular or square grid contains circles in some cells; a circle may have a number inside or not. The task is to blacken some cells of a grid according to the following rules:

• White cells form a path exactly one cell wide.
• Cells with circles are always white.
• A cell with a circle must have exactly one white cell adjacent to its side.
• A white cell without a circle must have at least two orthogonally adjacent white cells.
• A number in a circle indicates how many white cells can be seen horizontally and vertically from that cell, including the cell itself.
• All the white cells must be connected horizontally or vertically.
• No 2 x 2 cell area within the grid can have the same color.

Cross+A can solve puzzles from 3 x 3 to 30 x 30.