Heyawake

Heyawake (Japaneseへやわけ, dt divided spaces ) is a mystery, which is published by the Japanese magazine Nikoli. It first appeared in Puzzle Communication Nikoli 39 ( September 1992 ). A German name of the puzzle is Red Chaos.

Regulate

Heyawake is played on a rectangular grid. The grid is divided into small rectangles ( "spaces" ), which are surrounded by bold lines. Some of these rectangles bear a number.

The aim of the game is to determine which are the squares of the screen black and white which. The following rules apply:

• Black squares limits never over an edge to each other.
• All white squares are related by edges
• The numbers indicate how many black squares appear in a room
• A room without number can contain any number of black squares (as long as the other rules are met)
• A straight line of white squares may extend no more than two rooms.