Defending Digits (Castle Sudoku)
(Published on 14. October 2020, 12:26 by Mark Sweep)
Standard sudoku rules apply.
Standard castle wall rules apply: draw one closed loop through the grid without the loop crossing itself. The cells with arrows and a thick border are not part of the loop, but have the following requirements: the white cells must be inside the loop, the black cells must be outside the loop and any gray cell may be either inside or outside the loop. A digit in a cell with arrows shows the amount of times the loop crosses a cell border in the given directions.
In addition, digits that are adjacent on the loop (only the loop counts, not their position in the grid!) cannot be consecutive.
Solve on Penpa+
Solution code: Digits in row 8 from left to right, followed by the amount of loop turns in each row, starting from the top. So, 18 digits in total.
Comments
on 13. July 2022, 17:58 by StephenR
Thanks, enjoyed this and the interaction between castle wall and sudoku.
on 28. July 2021, 17:37 by Mark Sweep
Updated tags
on 19. October 2020, 11:06 by Mark Sweep
Thanks for your kind words @glum_hippo and @Djmelee3000! I'm glad you enjoyed it.
on 19. October 2020, 00:04 by glum_hippo
This was a lovely puzzle. It's rare for me to see such a frequent switching of attention between constraints. Really memorable effort! I wouldn't say the puzzle is too hard, but I must admit getting some help from @stefliew after breaking it temporarily...
on 16. October 2020, 03:04 by Djmelee3000
Loved it!! Thanks for this. Lots of fun and not too difficult.
