8-Color Theorem
(Published on 14. June 2022, 19:10 by the_cogito)
-Normal Sudoku rules apply.
-Digits may not repeat within killer cages.
-Every gray line is exactly one of the following constraints, each to be determined by the solver:
-Renban. A renban line must contain a set of distinct consecutive digits, in any order.
-German Whisper. Adjacent digits along a german whisper line must differ by at least 5.
-Lockout Line. Endpoints of a lockout line must differ by at least 4. Non-endpoint digits along the line may not fall between these endpoint values.
-Between Line. Digits that lie between endpoints must fall between the values of the endpoints
-Gray lines must NOT fulfill the requirements of more than a single constraint simultaneously.
-Every contraint appears exactly once.
Solve on CTC app
Solve on f-puzzles
Solution code: Row 6, left to right (9 digits).
Comments
on 28. September 2025, 10:34 by damo_89
Brilliant. The negative constraint works absolute wonders
on 9. September 2025, 09:04 by waffles_the_dog
Stunning puzzle, I really enjoyed the break in, and thanks to @the_cogito for helping out when I got stuck via my own confusion :D
on 5. September 2025, 09:36 by Fool on Hill
Stunning puzzle. Had to sleep on it. Not so very hard when the thoughts had time to coalesce.
on 4. September 2025, 16:37 by Bellsita
I loved this so much! Straight to favorites. Awesome puzzle!
on 20. June 2022, 13:01 by Angelo
Very hard, I needed some hints on it. but very satisfying!
on 16. June 2022, 19:40 by Snookerfan
Lovely hard puzzle! Very interesting logic to distinguish between the constraints and to make sure that the lines don't fullfill more than a single constraint.
on 15. June 2022, 22:03 by Statistica
Absolut großartig!
on 15. June 2022, 14:46 by ocaly
This puzzle is beyond me and I'm glad I got a tip from you during my solve. Really nice logic and I like this version more than the other one with fewer digits.
on 15. June 2022, 01:32 by Playmaker6174
The subtle craziness in this one, and what a way to execute the idea for the extra regions :)
on 14. June 2022, 23:18 by Andrewsarchus
A Very Clever Break-in! Great Puzzle!
on 14. June 2022, 19:12 by Niverio
Love to see ambiguity utilized like this!
