Range
Shade squares black so every number sees exactly its count
- Black
- –
- Dots
- –
Tap or click a square to use the chosen action; tap again to cycle it through black, dot and empty. Right-click dots. Arrow keys move; Enter acts as a left click and Space as a right click. Shift-arrows dot as you go; H gives a hint. Ctrl or ⌘ Z undoes; Shift Z redoes.
Progress saves on this device.
How to play
Shade some squares black. Numbers are never black, and no two black squares touch side by side.
The white squares must all connect into one area. Each number counts the white squares it can see looking up, down, left and right until a black square or the edge, counting itself.
Dots mark squares you know stay white; they are optional. Touching black squares, numbers that see too many or too few squares and white squares cut off from the rest turn red with a dashed outline. Undo and Redo follow your history; a new move after Undo replaces the old branch. Restart returns to the empty grid and can be undone. Hint fills in one square that follows from the board. Solve reveals the answer and does not count as solving the puzzle yourself.
Engine: Simon Tatham’s Range, contributed by Jonas Kölker to his Portable Puzzle Collection. MIT license and credits.