Just Some Clued Digits
(Published on 15. April 2026, 23:26 by mellowrobinson)
Chaos Deconstruction:
- Locate eight orthogonally connected regions in the grid, each containing the digits 1-8 without repeats.
- Digits do not repeat in a row or column.
- Cells not in a region do not contain a digit.
Japanese Sums:
- A number outside the grid gives the sum of a contiguous run of cell(s) that are in the same region in that row or column.
- Any such run must be flanked by empty cells or the grid edge.
- Runs are clued in the same order as they appear.
- In a row or column with a clue, all runs are clued.
- A * may represent any number of valid runs, including none. Runs noted by a * are not necessarily flanked by empty cells.
- A ? represents any digit 0-9, but no clues may have a leading 0.
To clarify, regions may only touch in two possible instances: where their runs are not clued, or where their runs are only clued by a *. See the example below and note the clues in rows and columns with touching regions.
Solve on Sudokupad
Solution code: Column 4, with 0s for empty cells and - for regions borders eg 12-0-345-6-000
Comments
yesterday, 09:06 by Snookerfan
Brilliant puzzle! I did not properly read/understand the rules at first and broke the puzzle soon. Then I looked at the clarification and it all made sense. A very beautiful and smooth puzzle. Thanks
on 16. April 2026, 13:23 by mellowrobinson
Added clarification about touching regions. Thanks everyone for helping me make the rules clearer. I'm working on other Japanese Sums puzzles with hopefully more intuitive rule implementation.
on 16. April 2026, 12:18 by oskode
Really cool and smooth, but I agree that it should be specified that ”no valid clues” include regions that touch. I onle got that after my second restart :’D
on 16. April 2026, 11:48 by Tyro533
I found the rules a bit confusing as i assumed each run in a * clue would each be considered "clued" since the row/column has a clue and the runs have to be "valid". Therefor i thought they would need to be separated by an empty space.
In retrospect i see now that the example shows that this is not the case but it's not how i would have interpreted the rules
on 16. April 2026, 09:08 by mellowrobinson
updated rules
on 16. April 2026, 08:38 by Clipper
Should the instructions include a note about the order of the clues matching the order of the runs?
-
Yes, thanks for pointing that out
on 16. April 2026, 06:34 by mellowrobinson
Fixed solution code
on 15. April 2026, 23:51 by Calvinball
Fab-u-lous!
