The Kropki Diagonal
(Published on 13. July 2023, 22:47 by gdc)
This one is similar to one of my last puzzles (#000EEH) but with a thematic arrangement for the dots. The dots now form a diagonal on their own! Seems like a "good fit" for the litte killer. Difficulty should be about 2,7 stars depending on your familiarity with knight's move logic. Have fun!
Rules
- Normal Sudoku Rules
- Place the digits 1 through 9 in each empty cell. Digits must not repeat within the same row, column, or box.
- Knight's Move Constraint
- Digits must not repeat in cells that are a chess knight's move apart.
- Black Kropki Dots
- A black dot between cells indicates cell values with a 2:1 ratio. Not all dots are necessarily given.
- Little Killer (25 diagonal)
- Digits along diagonals pointed to by arrows outside the grid must sum to 25. Digits may repeat along the diagonal if allowed by other rules.
Notation advice (minor spoilers ahead)
This is the notation I used during setting and testing the puzzle. I personally don't like using too many colors and think that 5 are enough for this puzzle.
Solution code: Row 1 (9 digits)
Comments
on 8. February 2025, 16:18 by oaklian
Spent ages struggling until I noticed the knight's constraint rule! After that it went a lot smoother :)
on 26. August 2024, 16:22 by ClayLovesLogic
https://www.youtube.com/watch?v=qjdtiuCGhL4&lc=UgyTP4e2zgdZ_MygiQd4AaABAg
Link to my solve. Excellent puzzle!
on 2. January 2024, 08:24 by gdc
restyle puzzle with sudokumaker
on 14. October 2023, 20:52 by sleeky21
yeah i liked that, thanks!
on 23. September 2023, 07:23 by cascadeshiker
I would have been lost without the comments suggesting coloring. I'd never figured out how to do that with Kropki dots before, so this was very educational for me. Thanks! (Actually I used letters instead of colors but the principle is the same)
on 23. August 2023, 10:45 by KingIsulgard
Very fun
on 21. July 2023, 19:44 by AlSina
Nice!!!
on 20. July 2023, 22:21 by Syzygy
That was SO much fun to complete! Thank you for setting this, I love colouring in, and luckily I stumbled upon the right method without the spoiler!!!
on 16. July 2023, 23:36 by fitzie
I was able to color all the way through. Just had to be careful towards the end when coloring 579 with some ambiguities left in the 2:1 pairs.
on 16. July 2023, 05:38 by gdc
Thanks for the comments! Really interesting to hear your opinions about notation. I think there is a strong case for letters instead of colors for difficult "coloring puzzles" like #000936. With my "coloring advice" I just wanted to showcase the easy coloring pattern that was sufficient for my test solves.
I am sorry if anyone needed to change notation midway through the solve because that is always painful :S
on 14. July 2023, 22:18 by HumanBirdsong
Fantastic puzzle, thanks!
on 14. July 2023, 16:44 by Barrels
Very nice!
on 14. July 2023, 15:26 by PinkNickels
Seen a few of these types of puzzles lately...kropki with knight's move and a little killer to disambiguate. love them! thanks for setting.
on 14. July 2023, 13:29 by UebungsleiterK
Great puzzle! Coloring is always lot of fun. For me it worked out perfectly to colour the dots and take letters for the 579s.
on 14. July 2023, 12:24 by puzzlepandit
very good and nicely enjoyable puzzle. I got confused in colors and letters and then converted everything to letter. The letter allocation was such that the couple of letters will map to couple of digits. That way I do not need to keep track of mapping.
on 14. July 2023, 07:36 by Silverscree
Oooh I already enjoyed the previous version of this puzzle, but these edits make it much better again! So smooth this time without that really tricky box 3 disambiguation. I've been loving your colouring puzzles @gdc!
on 14. July 2023, 06:14 by sanabas
I'd rather not mix colours & letters unless I need to, and I find it much easier to spot that a single cell can't be yellow or that yellow is forced in a row if yellow only represents a single digit, rather than yellow representing either 1 and 2 or 4 and 8 as in your example.
So easiest for me to just colour in the entire board before using the single clue to disambiguate everything. Think that makes it more a 1 or 1.5 star difficulty, too. Fun to do, either way.
on 14. July 2023, 04:10 by Calvinball
What good fun! And somehow I find this the perfect example of a 2.7* difficulty puzzle lol.
on 14. July 2023, 01:25 by WatermeRen
I know you mentioned you only use 5 colours, I got most of the way with 5 colours, then I got stuck a bit and started using 9 colours and was able to disambiguate where I was stuck, so could be helpful for others!
on 14. July 2023, 00:27 by DanishDynamite
Great fun!
on 13. July 2023, 23:49 by OutOfMyMindBRB
Loved it! Approachable, colorful and elegant, thanks for setting :-)
