Number Shade

Every cell holds a number, and some numbers repeat in their row or column. Shade cells to remove the repeats, following three rules: no number may appear twice among the unshaded cells of a row or column; shaded cells may not touch each other side by side; and all unshaded cells must stay connected in one group.

This style of puzzle is known in Japan as hitori. Each Game Oix puzzle is generated with exactly one solution.

1. Tap a cell to shade it; tap again to circle it (definitely unshaded); tap again to clear.
2. Remove every repeated number from each row and column by shading.
3. Shaded cells may only touch diagonally.
4. The unshaded cells must form one connected area.

• Sandwiches: in 4 7 4, the 7 can't be shaded… so one of the 4s must be — and the middle cell is safe.
• Neighbours of shaded cells are unshaded — circle them.
• Watch connectivity. A shade that would wall off a group of white cells is never right.