Roadblock
(Published on 28. April 2022, 17:59 by KNT)
The rules for the puzzle are as follows:
1) Place the digits 1 through 9 in every row, column and region, except the regions are to be determined by the solver.
2) Regions are all orthogonally connected.
3) A digit in a cell with an arrow indicates the total number of distinct regions between that cell and the edge of the grid in the direction of the arrow.
4) All possible arrows are given. That is, for any cell, in any direction that there is not an arrow present, then the number of distinct regions between that cell and the edge of the grid in that direction is not equal to the digit in that cell.
This ruleset and the negative restriction might be a bit confusing, so I have provided a 6x6 example puzzle that might serve as a simple, but beneficial warm up before attempting the main puzzle.
Penpa+ link to the 6x6 example.
And now, for the main course:
Penpa+ link to Roadblock.
For both this and the example puzzle, answer check is enabled with green edges and blue sudoku digits.
As always, have fun, and leave a comment if you enjoyed the puzzle, or need a nudge in the right direction.
Solution code: Row 2 followed by Column 7, 18 digits total.
Comments
on 9. February 2024, 16:44 by The Book Wyrm
Very fun puzzle!
Interesting ruleset - the negative constraint on something like this is not something I've seen before, and while it was a bit awkward to scan for at times, it led to some very interesting deductions.
Smooth solve path, and not that difficult either.
on 26. May 2023, 18:32 by Agent
Lovely puzzle, very original break-in logic!
on 16. May 2023, 14:32 by ibag
I love that moment when you finally get into the puzzle after having stared at it perplexingly for ages....
on 29. March 2023, 16:26 by StephenR
Beauty and the beast. A beast of a puzzle, and a beauty of a puzzle. Absolutely mesmerising, thanks KNT.
on 31. January 2023, 11:54 by sugardude
WOW... Oh my... Wow... This is hands down one of the CRAZIEST puzzles i've ever seen. I was like "There is no way this doesn't break" all the time. Absolutely insane. Thanks.
on 6. December 2022, 13:21 by ONeill
Brilliant puzzle :) I somehow managed to get through it without remembering the negative constraint, so I think I’ve missed some logic somewhere.
on 18. August 2022, 15:11 by Piatato
Very nice and smooth one! Not very hard at any point, but full of beautiful little deductions throughout.
on 10. July 2022, 19:44 by PrimeWeasel
Very hard , very nice, very sloppy with my solve.
on 9. July 2022, 04:06 by Christounet
Wow !! Another brillant chaos construction here ! Very challenging because you need to constantly scan with the negative constraint in mind. And boy, it does a lot in there ! Now I got to watch you solve it to compare with my own deductions. Thanks a lot for this !
on 3. May 2022, 18:24 by Niverio
A true scanning exercise! And a very trap-based ruleset. KNT is now added to my list of "evil" setters.
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>:)
on 3. May 2022, 00:52 by cmb
I can't emphasize enough how distinctly brilliant this puzzle is!
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Thank you for the kind comment, cmb! -KNT
on 30. April 2022, 22:29 by MagnusJosefsson
Very nice and fun puzzle! Was fairly smooth for me, enjoyable!
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Thank you, Magnus! I'm glad it was a smooth solve. -KNT
on 30. April 2022, 15:43 by henrypijames
OMG I've never seen a puzzle with such a powerful and sophisticated negative constraint (unlike a miracle sudoku where the negative constraint is overwhelming but much less sophisticated).
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Thank you, Henry! That means a lot coming from someone who has solved many difficult puzzles. -KNT
on 29. April 2022, 22:43 by Elliptical
I've solved many of your recent chaos construction puzzles. I think that one was probably the hardest of them. Great Puzzle. Keep them coming :)
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I agree, this is the hardest puzzle I have posted thus far. I do definitely intend on continuing to set many more CCs/puzzles in general, but this puzzle was very mentally taxing to create, and I'm likely going to take some sort of short break before setting a new one. Nevertheless, congratulations on solving the puzzle, Elliptical! -KNT
on 29. April 2022, 13:13 by Vebby
Wonderful puzzle! Some tricky steps but nothing unfair in my opinion. Nice rule-set. Thanks KNT! :)
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Thank you, Vebby! I'm so glad you enjoyed it! -KNT
on 29. April 2022, 02:18 by marcmees
respect for the testsolvers. :-)
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Haha. Before posting this, I definitely wanted a sanity check. I'm grateful to both Playmaker6174 and TotallyNormalCat for ensuring that at least the starting logic is not bypassable. Thanks for another solve, Marc! -KNT
on 28. April 2022, 21:54 by Jesper
Very nice and challenging, thanks!
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Thank you for the solve, and I'm glad you enjoyed it! -KNT
on 28. April 2022, 19:14 by Playmaker6174
That's quite an insane puzzle for me, couple of points during mid solves took me like forever to spot a deduction despite how smooth it looks at the beginning but its all worth it in the end. Incredible and lovely puzzle :)
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And thank you for being a great test solver! -KNT
on 28. April 2022, 18:07 by KNT
tags changed
on 28. April 2022, 18:02 by KNT
I am very happy with how this puzzle turned out, and while the solving path is not as narrow as some of the paths in my other puzzles, I think the logic in this one is quite interesting, and that this is a true 5/5 in difficulty.
I hope you at least attempt this, but I will warn it is fairly hard, as both of my test solves were over 2 hours. There is lots of difficult region geometry and negative restrictions required for the solve, and some challenging irregular sudoku steps as well. I have left a solution video in a hidden comment for anyone that solves, in case they want to compare solve paths.
I also do encourage you to try the 6x6 example puzzle before tackling the main one to familiarize yourself with the ruleset. Good luck!
