Negative Sandwich Sudoku
(Published on 7. August 2020, 19:15 by clover)
- The locations of all negative digits are highlighted in blue.
- The sum of the digits in each row, each column, and each 3x3 box is 1.
- The digit 7 is negative every time it appears in the grid.
- Numbers outside of the grid indicate the sum of the digits sandwiched between the (plus or minus) 1 and the (plus or minus) 9 in that row or column.
Penpa link: penpa
Solution code: Positive digits from rows 1 and 2
Comments
on 16. April 2021, 23:28 by DiMono
I can't speak for anyone else, but I actually really enjoyed this puzzle! There was a single small lookahead required as part of my break-in, but aside from that, I found the solve difficult but smooth.
on 29. December 2020, 05:53 by RockyRoer
Whew! Finally got it!
on 11. August 2020, 13:53 by bosjo
Nice puzzle! After a false start, which luckily led to an immediate halt, the solve proceded fairly smoothly.
on 9. August 2020, 14:57 by emmettcito
Took me a bit to wrap my head around this puzzle, but once I got going it got smoother and smoother. Nice puzzle :)
As for the difficulty I think this is 4 stars
on 9. August 2020, 12:33 by clover
Added Youtube link of an explanation for how to begin
on 8. August 2020, 17:18 by clover
Corrected penpa link
on 8. August 2020, 17:15 by clover
Included Penpa link
