Shimaguni

Shimaguni is a logic puzzle published by Nikoli. A rectangular or square grid is divided into regions. The goal is to blacken some cells in each region according to the following rules:

• All black cells in a region must be connected.
• A cell with a number indicates how many cells in the region must be blackened.
• In regions without a number any amount of cells may be blackened (at least one).
• Two regions with the same amount of black cells must not be orthogonally adjacent.
• When two cells are orthogonally adjacent across a region boundary, at least one cell must be white.

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