Irasuto

Irasuto ("Illustration") is a logic puzzle created by Naoki Inaba (Japan). A rectangular or square grid contains white and black cells with numbers. The goal is to blacken some cells of a grid according to the following rules:

• A number in a white cell represents the number of empty white cells that can be seen from that cell.
• A number in a black cell represents the number of empty black cells that can be seen from that cell.

Cross+A can solve puzzles from 4 x 4 to 30 x 30.