Sum Line Sudoku #1
(Published on 1. October 2022, 10:02 by Phistomefel)
- Fill the grid with the numbers from 1 to 9 so that in each row, column, and 3x3 block, each digit occurs exactly once.
- For every triple of adjacent digits on a line, one of the digits has to be the sum of the other two, e.g. 2-5-7, 6-9-3, and 8-4-4 are valid adjacent digits along a line. Digits may repeat on a line if allowed by the other rules.
Here you can find a link to solve the example online.
The puzzle is also available online via F-Puzzles and CTC-App. Have fun solving!
NB: Each line in the shape of a Y consists of three lines, each of three cells length. For instance, the line running in boxes 1 and 4 contains the three lines R2C2-R3C2-R4C1, R2C2-R3C2-R4C3, and R4C1-R3C2-R4C3.
Solution code: First and last column
Comments
on 2. September 2023, 22:20 by marcmees
Thanks.
on 26. March 2023, 21:33 by peter.rietmann
Thank you this was such a joy to complete.
on 3. November 2022, 16:25 by meixia
Great puzzle. The Y-shaped lines are very potent with this rule. I am now intrigued to attempt the #2.
on 4. October 2022, 14:24 by OGRussHood
The sudoku devil does it again! The perfect puzzle with the given ruleset.
-------
Thank you very much, OGRussHood! Nevertheless, I hope that this puzzle is not perfect, because otherwise there would be no need for other puzzles of that variant. :)
on 4. October 2022, 10:16 by tesseralis
The logic at the beginning was pure Phistomefel elegance. It's surprising how restricted these lines become--I look forward to what else you can cook up with these!
-------
I have the feeling I should insert some evil laughter here. ;)
on 3. October 2022, 21:44 by antiknight
I remember this being a gorgeous puzzle especially the break-in ! Thanks for sharing Phistomefel :)
-------
Reply: Thank you so much for the kind words, antiknight!
on 3. October 2022, 14:02 by DaniK
I really liked the condition, the Ys were very satisfying to unfold. Thanks for this beautiful puzzle!
-------
Reply: I am glad that you enjoyed the logic. Thank you so much, DaniK!
on 3. October 2022, 02:49 by Vebby
Very cool! I look forward to future explorations of this ruleset. Thanks Phisto :)
-------
Thank you, Vebby! I feel that this variant has potential - at least for some interesting geometric shenanigans.
on 2. October 2022, 21:47 by cmb
Y?!
-------
(:
on 2. October 2022, 20:30 by DiMono
This was an excellent introduction to this rule. The Ys worked really well together. Looking forward to more of this.
-------
Reply: Thank you so much for the kind words, DiMono! I actually wasn't sure whether this is suited as an introductory puzzle because of the Ys. So this is a good to hear.
on 2. October 2022, 19:58 by Tilberg
Sehr verdächtig, daß im Beispiel kein Y vorkommt! :-D
Hat Laune gemacht. Danke!
-------
Antwort: Na so was! Muss ich doch glatt übersehen haben. ;)
on 2. October 2022, 19:13 by Jorrr2
I didn't see it was a phistomefel puzzle until I solved it. Happily surprised! Also I've only managed to solve two 4-star puzzles, but this one didnt really feel difficult to me. 3,5 stars maybe? Pretty nice!
-------
Reply: I agree. Before I published it, I wasn't sure whether to give it a 3 or 4 star rating, but I thought that the break-in might be a bit much for a 3 star puzzle.
on 2. October 2022, 18:50 by drbs
Very nice, the first time I needed to check the logic with pen and paper. :-)
-------
Reply: I can imagine. :)
on 2. October 2022, 09:29 by Christounet
A good way to start off on a sunday morning ! The "Y" stuff is of rare beauty (both in concept and design), and not that hard to figure out. Thanks++.
-------
Reply: Thank you so much, Christounet! And I am very glad that you found the Y logic approachable.
on 2. October 2022, 07:48 by laky
the logic of “y” is amazing
-------
Reply: That is great to hear! Thank you, laky!
on 2. October 2022, 01:27 by Playmaker6174
Very Lovely! The Y logic were fun to seek, then the solve remained fun and fascinating till the end, got a bit trouble as well but I managed to handle it successfully. I hope to see the next part(s) :)
-------
Reply: Thank you, Playmaker! Right now, only one more part is planned, but who knows. :)
on 2. October 2022, 00:13 by PulverizingPancake
I had a lovely time with this one! The difficulty felt super consistent throughout the puzzle. One of my favorites from you in a while!
-------
Reply: Thank you so much, PulverizingPancake! I think that keeping the difficulty at a more or less constant level is easier when the individual steps are not so hard.
on 1. October 2022, 21:47 by Rivz
Had to triple-check the Y logic lol, but the whole thing was a beauty.
-------
Reply: I can definitely relate to that - I had to check the logic several times, as well. (:
on 1. October 2022, 21:21 by AKernel
Lovely puzzle.
And my 100th solved puzzle on Logic Masters. I can't imagine a better puzzle for such a jubilee.
Big thank you!
-------
Reply: Thank you so much, AKernel! I am very glad you chose this puzzle for your 100th solve on the side. :)
on 1. October 2022, 17:46 by Klausku
Die Y haben mir erst das Hirn zerbröselt. Als das aber klar war, ging das Puzzle geschmeidig zu lösen. Hat mir sehr gut gefallen. Danke schön. Endlch mal ein Phistomefel-Rätsel in unter einer Stunde. Bin gespannt auf die schwierigere Variante.
-------
Antwort: Es freut mich, dass dir das Rätsel gefallen hat. Deine Reaktion spiegelt ziemlich gut wieder was ich erwartet hab: der Einstieg ist ein wenig schwieriger, aber dafür sollte der Rest halbwegs entspannt von der Hand gehen.
on 1. October 2022, 16:47 by KNT
looking forward to the harder one, phistomefel! the Y shaped lines in this one were already really interesting.
-------
Reply: Thanks, KNT! The harder puzzle will mainly make use of other kinds of logic that the sum lines offer.
on 1. October 2022, 16:24 by Snookerfan
Very nice puzzle, loved the Y's. Thank you!
-------
Reply: The Ys were the reason I made this puzzle. So, I am very glad to hear you enjoyed the logic. :)
on 1. October 2022, 15:08 by Jesper
Fun and approachable, thanks!
-------
Reply: I am glad you had fun with the puzzle. Thank you, Jesper!
on 1. October 2022, 13:10 by Phistomefel
@Qodec: That is great to hear! I already have a follow-up puzzle in store which will be a bit more difficult.
@Piatato & @thoughtbyte: Thank you so much for the nice comments!
on 1. October 2022, 12:55 by thoughtbyte
Cool idea and a great puzzle to introduce it. Thanks!
on 1. October 2022, 12:31 by Piatato
Great fun! Nice variant and a lovely puzzle! :-)
on 1. October 2022, 12:24 by Qodec
What a perfect introductory puzzle! Would love to see more!
