Snake-Sums Sudoku
(Published on 18. September 2020, 17:40 by Willy Wonka)
This puzzle is a variation on X-sums sudoku which I have not seen before. I hope you enjoy!
Rules:
Normal sudoku rules apply. Every row, column and box must contain the digits from 1-9.
Clues outside the grid indicate the sum of digits in a snake of length X where X is the first digit in the row or column.
Snakes begin at the cell directly next to a clue and are 1 cell wide regions where digits cannot repeat. A snake cannot touch itself orthogonally and cannot branch in 2 directions. No cell can be a part of more than 1 snake.
The photo below demonstrates invalid snakes on the left and valid snakes on the right.
The reasons they are invalid are as follows:
10 clue - the snake does not start at the first cell next to the clue.
20 clue - the snake is not 1 cell wide.
30 clue - the snake length is not given by the first cell.
And here is the puzzle!
I would love to know if you enjoy the puzzle! Happy solving :)
Solution code: Row 2 and column 7
Comments
on 28. April 2024, 04:42 by Willy Wonka
Updated online solving links
on 13. October 2020, 14:38 by Madmahogany
Incredible execution of a very interesting ruleset!
on 23. September 2020, 12:24 by Nylimb
Great puzzle!
Like some previous solvers, I made several mistakes. I solve with paper and pencil, but I've gotten in the habit of taking pictures of my progress every few minutes, so I can backtrack without having to start over each time. That was very useful for this puzzle.
@Nylimb Thank you! I find that very impressive, pen and paper would be too challenging for me with many Sudokus but taking photos would definitely help. I might try it sometime because I spend a lot of time in front of a screen lately! I'm pleased that you enjoyed the solve :)
on 21. September 2020, 04:29 by Willy Wonka
@PixelPlucker @Phistomefel I'm glad you both enjoyed it despite the mistakes! Thank you for sticking with it :)
on 21. September 2020, 03:12 by Phistomefel
Wonderful puzzle, but I found it very tough. This is probably the puzzle, where I made the most mistakes. I had to start over numerous times, but I am very glad that I did.
on 20. September 2020, 13:29 by PixelPlucker
Very challenging! I made so many careless mistakes and had to backtrack multiple times. Really elegant logic :)
on 19. September 2020, 23:40 by Willy Wonka
Thank you everyone for your lovely comments!
on 19. September 2020, 22:26 by marcmees
excellent puzzle ... maybe a follow-up with big sums?
@marcmees potentially! Currently in f-puzzles you cannot write an outside clue higher than 35 but there is still a lot of room to increase the sums!
on 19. September 2020, 21:52 by Jesper
Excellent! Well designed.
on 19. September 2020, 17:12 by harrison
Very elegant setting, with a logical solution path!
on 19. September 2020, 05:58 by cdwg2000
Nice!
This is a variant of X-Sums Sudoku. Recommended variant name: Line X-Sums Sudoku.
@cdwg2000 I am pretty happy with the name but I appreciate the suggestion! I will include "Sudoku" at the end so it is clearer when browsing through the portal
on 18. September 2020, 23:43 by Djmelee3000
Brilliant puzzle! First one I've solved from you and it was a good challenge.
on 18. September 2020, 20:20 by Dandelo
Very nice puzzle!
on 18. September 2020, 18:59 by Willy Wonka
Rule clarification
on 18. September 2020, 18:39 by DiMono
Wonderful puzzle.
@DiMono Cheers!
on 18. September 2020, 18:06 by Dandelo
And may a snake touch itself orthogonally without covering a 2x2-region? (Here not possible, because 30 is the largest clue.)
@Dandelo I have fixed the rules so hopefully it is clear now!
on 18. September 2020, 18:02 by Dandelo
Are T-shaped regions allowed?
on 18. September 2020, 17:46 by Stavros96
A stunning solve from beginning to end! Loved it
@Stavros96 So glad you enjoyed it! Thank youu :)
