Negative Sevens
(Published on 13. August 2021, 19:53 by jwsinclair)
Normal sudoku rules apply.
Cages show their sums. All possible two-cell cages that sum to 7 are given.
Along gray lines, which can have any length and can move orthogonally and diagonally, digits have a difference of exactly 7. All possible gray lines are given.
Along thermometers, digits increase from the bulb end.
f-puzzles
CtC
Solution code: row 1, row 9 (18 characters, no spaces)
Comments
on 6. March 2026, 14:49 by isajo4002
Took me a while to figure out how to even start thinking about this but once I did it flowed beautifully. Thank you for this amazing puzzle!!
on 1. June 2024, 13:35 by mezkur7
Sudokupad: https://sudokupad.app/42oco0nzs8
on 9. May 2023, 15:07 by StephenR
Good job, thanks. Spotting the negative constraint is always fun and sometimes surprisingly elusive.
on 30. May 2022, 03:26 by PinkNickels
Amazing puzzle!
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Thanks!
on 15. August 2021, 13:13 by henrypijames
Understood the logical consequences of the negative constraint fairly quickly, but had to restart a couple of times due to dumb mistakes.
on 14. August 2021, 21:34 by jwsinclair
@Innocuous,
Sorry, I'm not sure I understand your question, but the lines can have any length as long as they are connecting adjacent cells with a difference of 7 (i.e. 1818... or 2929...). The fact that the lines are short tells you that there are no such sequences longer than two cells in the puzzle.
on 14. August 2021, 21:15 by Innocuous
:edit: Nevermind! I had mis-read part of the rules
on 13. August 2021, 20:39 by kolot
Very nice!
