Riverbank - Episode 3: Watch on the Rhine
(Published on 6. May 2022, 14:48 by henrypijames)
- Normal sudoku: Fill every row, column and marked 3×3 box with the digits 1 to 9 once each.
- River & riverbank: Locate a river (think: classic snake) in the grid, consisting of a one-cell wide, non-looping, non-branching string of orthogonally connected cells, which may not touch itself orthogonally (but may diagonally); each border between a river cell and a non-river cell is a riverbank segment (this precludes the grid edge from being counted as riverbank).
- Riverbank sweeper: Each circled cell is a riverbank sweeper, which counts riverbank segments within the (up to 3×3) surrounding cells (see example image - but ignore the squared sentinel which is irrelevant for this puzzle).
- German whispers: Neighboring cells along the river differ by 5 or more.
- No negative constraint: Not all circles are necessarily given.
To familiarize yourself with the riverbank ruleset, please consider first taking a look at the 6×6 introductory puzzle Episode 2: Adobe Illustrator.
- Download this puzzle as: scalable image (SVG) | bitmap image (PNG) | printable document (PDF).
Note: SVG auto-switches colors depending on light/dark mode in system/browser setting; PDF is in printing-friendly black on white. - Play online on: Penpa+ | CtC App.
The riverbank ruleset is based on Borderline by @Jakhob & @wooferzfg.
Solution code: Row 3 & column 4 (left to right & top to bottom, 18 digits)
Comments
on 24. May 2024, 18:33 by Christounet
Great minimal setting ! The ending is quite magical. Thanks :)
on 26. January 2023, 07:20 by bodemeister
Very enjoyable puzzle. Thanks!
on 30. September 2022, 23:53 by codewizard
That was brilliant. Thank you! Took quite a bit of effort to get my head around, but got rewarded.
on 4. August 2022, 20:35 by lerroyy
very nice puzzle with a smooth solve! thanks
on 3. August 2022, 18:48 by Vebby
Wow, awesome logic! Had to stare for a while before realizing the key deduction after which everything flows beautifully.
on 11. May 2022, 12:30 by henrypijames
Switch puzzle image to light mode based on feedback
on 7. May 2022, 05:05 by henrypijames
Update example image
on 7. May 2022, 03:44 by henrypijames
Minor correction on rules phrasing
on 7. May 2022, 02:09 by twobear
Great puzzle! Lots of beautiful deductions throughout.
on 6. May 2022, 17:15 by henrypijames
Title correction
on 6. May 2022, 17:02 by henrypijames
Minor correction on rules phrasing.
on 6. May 2022, 16:43 by Jesper
Good one, thanks! Looking forward to those sentinels...
on 6. May 2022, 16:06 by kolot
Wonderful puzzle with some very beautiful and original logic.
