Use every clue to shade duplicates without touching black cells or disconnecting white space; the shipped board has exactly one checked solution.
Hitori begins with a grid of numbers containing deliberate row and column repetitions. Shade some cells so every visible number is unique in its row and column. Shaded cells may never touch orthogonally, and all unshaded cells must remain one connected region. The answer is therefore a topology problem as well as duplicate removal. A binary shade search checks adjacency early and connectivity at completion, stopping if a second solution appears.
Tap a numbered square or focus it with the arrows, then use OK to cycle visible, shaded, and circled. A circle is a player note that protects a number but does not itself satisfy a rule. Reset removes all personal marks while keeping the printed grid. Shaded cells turn dark, circles receive a ring, and the gold frame shows exactly which number the next action affects.
Score increases when a shade removes a required duplicate without creating an adjacent black pair, and when a confirmed visible number belongs to the connected final region. The progress meter compares decisive marks with the verified pattern; decorative cycling is ignored. Invalid states can be repaired freely, supporting endless practice. Completion requires uniqueness, non-touching shades, and one white component before the local best is updated.
When identical numbers share a row, at least one must be shaded. If two duplicates sit beside each other, one is black and the cells immediately outside that pair must remain white. A number between two identical neighbors is forced white because shading it would leave touching black cells when the duplicates are resolved. Before shading a bridge-like square, trace another white route around it so connectivity is not severed.
Phone players can use cursor controls to inspect dense duplicate groups without hiding digits under a fingertip. Buttons keep their forty-four-pixel minimum and the canvas fits dynamic portrait or landscape height. Debug mode demonstrates shade and protection choices while avoiding a permanent terminal screen. render_game_to_text exposes shaded adjacency, remaining duplicate groups, white-region connectivity, cursor, notes, progress, and the uniqueness-search result.
When identical numbers share a row, at least one must be shaded.
Phone players can use cursor controls to inspect dense duplicate groups without hiding digits under a fingertip.
Hitori: Score increases when a shade removes a required duplicate without creating an adjacent black pair, and when a confirmed visible number
Use every clue to shade duplicates without touching black cells or disconnecting white space; the shipped board has exactly one checked solution.