Range

Game Rule: Colour some squares black, so as to meet the following conditions: No two black squares are orthogonally adjacent. No group of white squares is separated from the rest of the grid by black squares. Each numbered cell can see precisely that many white squares in total by looking in all four orthogonal directions, counting itself. (Black squares block the view.) Left-click to colour a square black. Right-click to mark a square with a dot, if you know it should not be black.