Heyawake

[from Nikoli website]

The rectangle, divided by bold lines, is called "Room". Each number indicates how many painted cells exist in its room, while no number rooms may have any number of painted cells. Paint cells under following rules:

1. White cells must not exceed two rooms in a straight line.
2. The painted cells must not be orthogonally connected.
   
3. White cells must not be (orthogonally) separated by painted cells.

Solution: