Staying Connected
(Published on 21. August 2025, 08:00 by Kaktuslav)
This is a Fog of War puzzle. You can play it on SudokuPad: https://sudokupad.app/b0ki2ud1vy
Rules:
- Normal Sudoku rules apply.
- Shading: Shade some cells in the grid so that no 2×2 square is entirely shaded or entirely unshaded.
All unshaded cells must form a single orthogonally connected region (i.e., any two unshaded cells can be joined by a path of unshaded cells moving only between cells that share a side).
All shaded cells must form a single diagonally connected region (i.e., any two shaded cells can be joined by a path of shaded cells moving only between cells that share exactly one corner). - White lines: A digit on a white line indicates the total number of cells of the same shading in the cell's entire row and column combined, including itself.
- Shading sum lines: Gray lines act as region sum lines with respect to the two regions (shaded and unshaded): changes of shading divide the line into segments of equal sums (these sums may differ between lines). NB If a line lies entirely within one region, it serves only a decorative purpose.
- Dynamic fog of war: The grid is partially covered in fog. Entering correct digits may (but does not have to) clear fog somewhere in the grid. No guessing is required.
Solution code: Row 9
Comments
on 4. September 2025, 06:33 by Kaktuslav
Implemented better phrasing of the white lines rule suggested by QuiltyAsCharged, thank you!
on 4. September 2025, 03:36 by QuiltyAsCharged
This is brilliant! It's an interesting variation on yin- yang that requires you to throw out everything you knew about yin-yang, and discover new patterns.
However, the rule about white lines did confuse me for quite some time. Typically in puzzles with shading, the word "seen" indicates that the opposite shading blocks vision, but that is not the case here.
A digit on a white line indicates the total number of cells of the same shading in the cell's entire row and column combined, including itself.
on 22. August 2025, 06:36 by Elliott810
Brilliant puzzle! Thank you:)
