Clock Faces Sudoku
(Published on 21. August 2020, 16:50 by Phistomefel)
The rules are taken from Richard's puzzle.
Apply classic sudoku rules. Four digits around a white circle are placed clockwise in a strictly increasing order starting from any one of the four cells. Four digits around a black circle are placed anti clockwise in a strictly increasing order starting from any one of the four cells. All possible circles are marked.
The puzzle is also available online via F-Puzzles. Have fun solving!
Solution code: First and last column
Comments
on 21. October 2021, 17:43 by dissonance
Wow,what a tricky puzzle !
Thanks for sharing.
on 21. August 2021, 18:44 by Phistomefel
Added tag "Online solving tool".
on 6. July 2021, 20:24 by Arka Badarka
Took me a while to realize how powerful the negative constraint was in this rule set. Really enjoyed the puzzle!
on 26. June 2021, 16:21 by glum_hippo
No need to apologize, haha! If I hadn't been so impatient, the whole drama could have been avoided. Such a delightful puzzle!
on 26. June 2021, 14:44 by Phistomefel
Thanks to glum_hippo for the f-puzzles link.
on 26. June 2021, 14:43 by Phistomefel
Thank you for giving the puzzle a try, glum_hippo, and for persevering. Sorry that I did not spot your hidden comment in time and thanks to cdwg2000 for the help.
on 26. June 2021, 09:10 by glum_hippo
In case anyone would like an f-puzzles link: https://f-puzzles.com/?id=ydm7v5gu
on 26. June 2021, 07:40 by glum_hippo
Truly fiendish, but glad to have it in the rear-view mirror. Thanks cdwg2000 for the affirmation. (I deleted my hidden comment asking to have my partial solve verified)
on 29. September 2020, 18:49 by DiMono
I'm one of the few! This must be what Simon feels like all the time. I had fun.
on 14. September 2020, 10:57 by Phistomefel
Increased difficulty rating
on 23. August 2020, 11:23 by Phistomefel
@Jesper,@emmettcito,@Arashdeep Singh:
Thanks a lot of your wonderful comments. :)
on 23. August 2020, 07:48 by Arashdeep Singh
Great puzzle. Absolutely enjoyed it :)
on 22. August 2020, 20:38 by Ours brun
I have to second Christoph here - my comment either was absolutely not targeting you, Richard. It was not at all aimed at correcting anything, I just felt like adding a bit of trivia since I have taken part in many competitions authored by Jan and happen to be very familiar with this variant - despite myself!
on 22. August 2020, 14:00 by Realshaggy
Richard, that was not my intention, sorry if it felt like that. But since we had a few recently, new people might think this is a new variant while in fact it is very old. I just wanted to mention the origin somewhere. As Bastien said, Jan stated that it is one of his favourites. (And I also hate them with a passion because I always break them.)
on 22. August 2020, 13:27 by emmettcito
Beautiful opening! Beautiful puzzle.
on 22. August 2020, 12:28 by Phistomefel
Credits to Jan Novotny.
on 22. August 2020, 12:23 by Phistomefel
@Christoph and @Ours Brun:
Thank you for pointing out the inventor of the puzzle. I'll add it to the description.
@Ours Brun: I am humbled that you try this puzzle despite not liking the variant a lot. Thank you!
on 22. August 2020, 11:04 by Richard
If I interpret the comments of Realshaggy and Ours Brun right, I feel like I am being corrected for being the inventor of this type. I never claimed to be the inventor, and I have written sound and clear at my version of CF where my inspiration came from. :-)
on 22. August 2020, 10:02 by Ours brun
Hello there. As Christoph said, Jan Novotny most certainly invented this type. He also stated that it is his favourite one, and if you ever take part in a Czech competition you can expect that there will be at least one or two of these to solve. It is personally a variant I don't like much, so I hope this one will help change my mind.
on 22. August 2020, 03:59 by cam
@peterkp Yes. I think what's going on is that "never decreasing" doesn't read as well since it's a negation.
on 22. August 2020, 02:00 by peterkp
@Gestern, Thanks for replying. So checking that I've understood you correctly, do "monotonically increasing" and "not decreasing" mean the same thing?
on 22. August 2020, 00:42 by Realshaggy
The type was probably invented by Jan Novotny from Czech Republic. You can find dozen of those in his "Krteks Cup" on fed-sudoku.eu, starting from 2009.
on 22. August 2020, 00:34 by Jesper
Great puzzle! Absolutely genius break-in. Loved it!
on 21. August 2020, 23:16 by Narayana
@peterkp
"monotonically increasing" =
increasing or remaining constant.
For example a sequence: 123334556.
Versus "strictly increasing" e.g. 123456789.
The meaning of mono means one so just one-tone or one behavior as opposed to a sequence that goes up and down.
Hope this helps.
Note that for clocks you are on a ring so something like 1289 can be read 2891, 8912, or 9128.
Not trying this puzzle yet, have to solve Cam’s first, also life is about to start getting back on the way of puzzles. Scary fall semester!!!
on 21. August 2020, 23:04 by Phistomefel
@MagnusJosefsson: Although I've checked the puzzle time and time again, I cannot assure you 100 percent that it is correct. I think it would be best, if you posted a link to a screenshot that shows the constellation where you get a contradiction, in a hidden comment.
on 21. August 2020, 22:58 by peterkp
Hi, can someone please explain what "monotonically increasing" means in the instructions?
on 21. August 2020, 22:54 by cam
I also made a puzzle with this ruleset this week! What a strange coincidence :) Clearly Richard made a wonderfully inspirational puzzle
on 21. August 2020, 22:32 by MagnusJosefsson
Is it correct as stated that all possible circles are marked? I keep getting contradictions when utilizing this negative restriction. But possibly I am misunderstanding the rules somehow.
on 21. August 2020, 19:41 by Phistomefel
Whoops! Sorry for the wrong link. It is fixed now.
on 21. August 2020, 19:41 by Phistomefel
Corrected Penpa-Link
on 21. August 2020, 17:11 by Greg
Penpa links to your previous starbattle puzzle :-)
on 21. August 2020, 17:09 by aneoid
I'm sorry, is the Penpa link wrong or is it just me?
on 21. August 2020, 17:09 by henrypijames
What's happening? Is it clock sudoku week? Or is the CTC Discord group having something like "time" as its theme of the month?
