Kropki Sums
(Published on 19. December 2021, 16:26 by mathpesto)
My first attempt at creating a Japanese Sums puzzle! Comments and ratings are much appreciated, and please be sure to check out my other puzzles here.
Rules:
Within the main 9x9 grid, normal sudoku rules apply.
Kropki: A white dot between two cells indicates that the numbers are consecutive. A black dot between two cells indicates that the numbers are in a 2:1 ratio. A gray dot means the numbers are consecutive and/or in a 2:1 ratio. Not all dots are necessarily given.
Japanese Sums: Shade cells within the main 9x9 grid so that the clues outside the grid equal the sums of the digits in contiguous blocks of shaded cells in that row/column. Blocks must be separated by at least one unshaded cell.
(Note: The number of clues for a particular row/column is exactly the number of white cells outside the grid for that row/column. (For example, column 6 has three white cells outside of the grid, so there are exactly three clues in column 6.)
(Also note: Numbers outside the main 9x9 grid don’t have to adhere to normal sudoku rules (e.g. they can be greater than 9, they can repeat in the row/column, etc.).
Solve on Penpa+ (thanks Vebby!)
SPOILER ALERT Walkthrough of Solution
Puzzle:
Solution code: Enter rows 8 and 9 (18 digits, no spaces)
Comments
on 13. March 2023, 22:09 by picoton
this is a brilliant construction! even in a grid like this one, you managed to guide me to the solution in a very smooth way! thanks!
on 24. December 2022, 13:54 by mathpesto
Added penpa link
on 23. June 2022, 07:45 by AnnaTh
Perfekt holiday pleasure!
on 12. April 2022, 17:51 by Mody
Superschön mit vielen kleinen logischen Schritten.
Super beautiful with many small logical steps
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Thanks so much! I've noticed you're on a roll solving my puzzles; I appreciate it! -mathpesto
on 28. December 2021, 15:58 by mathpesto
Removed unnecessary dot and updated links.
on 20. December 2021, 05:50 by fpac
loved it! took about 80 minutes trying to keep whittling down the possibilities of the shaded cells.
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@fpac Great! Glad to hear you loved it!
on 20. December 2021, 04:22 by fpac
ok. the 2 digit thing helps.
Thanks!
on 20. December 2021, 03:49 by mathpesto
Added walkthrough of solution
on 20. December 2021, 03:03 by fpac
in rows 2 and 3 outside the grid, you have a 9 consecutive to an 8, which then is consecutive to a 7 or 9. that ends up being in a cell with a black dot which doesn't work.
or am i missing something?
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@fpac Outside the grid, normal sudoku rules don't apply, so you can have two-digit numbers in those cells. For example, Clue 4 of Row 2 could be an 8, but it could also be a 10; the black dot from a 7 or 9 could be connecting to a 14 or 18; etc.
I also just wrote up a walkthrough and linked to it in the description above if you're looking for additional hints :)
