Dutch Flat Mates: Hot and Cold Lines
(Published on 7. August 2024, 10:30 by marty_sears)
Thrilled to create another puzzle for Flinty's fantastic Dutch Flat mates series. This puzzle was my experiment to see if it would be possible with the DFM ruleset to have the three middle rows of the sudoku completely empty. Turns out it was, but only just!
Rules:
- Normal sudoku rules apply.
- 5's live in Dutch Flats: Every 5 in the grid must have a 1 directly above it or a 9 directly below it. It may have both, but it doesn't need both.
- Hot and cold lines: Any red line has a higher total than any blue line.
Please leave a comment if you enjoy :)
Previous puzzles in the Dutch Flat Mates series:
- #01 - 18 Oct 23 - Classic
- #02 - 25 Oct 23 - Thermometers
- #03 - 01 Nov 23 - German Whispers
- #04 - 08 Nov 23 - Region Sum Lines
- #05 - 15 Nov 23 - Sandwich Sums
- #06 - 22 Nov 23 - Little Killer
- #07 - 29 Nov 23 - Kropki
- #08 - 05 Dec 23 - Zipper Lines
- #09 - 12 Dec 23 - Renban - By GoodCity
- #10 - 19 Dec 23 - Nabner - By GoodCity
- #11 - 26 Dec 23 - Skyscrapers - By GoodCity
- #12 - 03 Jan 24 - Dutch Whispers
- #13 - 10 Jan 24 - Killer Cages
- #14 - 17 Jan 24 - Arrows
- #15 - 24 Jan 24 - Ten Lines
- #16 - 31 Jan 24 - 159 Index and Even - By GoodCity
- #17 - 07 Feb 24 - Friendly Cells
- #18 - 14 Feb 24 - Quads
- #19 - 21 Feb 24 - Silent Killer - By GoodCity
- #20 - 28 Feb 24 - XV and Equality
- #21 - 06 Mar 24 - X-Sums
- #22 - 13 Mar 24 - Numbered Rooms - By GoodCity
- #23 - 20 Mar 24 - Diagonal X-Sums
- #24 - 27 Mar 24 - Yin Yang (Neighborhoods) - By Palpot
- #25 - 03 Apr 24 - Hit Points
- #26 - 10 Apr 24 - Counting Circles
- #27 - 17 Apr 24 - XY Difference - By GoodCity
- #28 - 24 Apr 24 - Double Sandwich Sums
- #29 - 01 May 24 - Foggy Knights
- #30 - 08 May 24 - Look and Say Little Killer
- #31 - 15 May 24 - Slingshot - By GoodCity
- #32 - 22 May 24 - 258 Index and Odd
- #33 - 29 May 24 - Rellik
- #34 - 05 Jun 24 - Search 9 - By Palpot
- #35 - 12 Jun 24 - Diagonal Outside
- #36 - 19 Jun 24 - Entropic Snake - Collab with Palpot
- #37 - 26 Jun 24 - Rossini - By GoodCity
- #38 - 03 Jul 24 - Pointer Arrows
- #39 - 10 Jul 24 - Same Difference - by Marty Sears
- #40 - 17 Jul 24 - Battenburg and Average Arrows
- #41 - 24 Jul 24 - Omnipotent Lines - by Sujoyku
- #42 - 31 Jul 24 - Modular Snake
- #43 - 07 Aug 24 - Hot and Cold Lines - by Marty Sears
Solution code: Row 5 from left to right
Comments
on 14. August 2024, 18:01 by sujoyku
Smooth as silk! Thank you for this fantastic puzzle, marty_sears! Figuring out the relationship between hot and cold lines and their effect on the DFM constraint has been huge fun.
on 10. August 2024, 20:18 by ChinStrap
One of my favorite setters doing one of my favorite rulesets. Loved your first DFM and this was another joy to solve. The grid looks more intimidating than it actually is.
on 10. August 2024, 14:04 by apiyo
Very smooth :)
(my solve at https://www.youtube.com/watch?v=V8WNwqZV_kA)
on 9. August 2024, 03:50 by Nightingale's Code
Really nice puzzle with some fun constraints working together beautifully. Thanks for sharing!
on 7. August 2024, 21:50 by baku
What a awesome puzzle! Thanks for sharing this pearl! I loved the interaction for the first digit, and there's a ton of small deductions all over the solving. Very fun and approachable puzzle!
on 7. August 2024, 16:56 by HumanBirdsong
I used the 'Dutch Flats' constraint once near the beginning, and then forgot it for most of the rest of the puzzle. You can get quite far just using maths - I had almost all of rows 1-3 and 7-9 resolved, but eventually became stuck and re-read the rules! So, for me, it was very difficult, but a lovely puzzle!
on 7. August 2024, 15:55 by Prof.Dori
Brilliant puzzle from start to finish. Really enjoyed this one, as expected from marty!
on 7. August 2024, 12:43 by Franjo
Incredible that this Dutch Flag Mate really exists - and you even made an approachable puzzle out of it! Thank you very much for sharing this gem.
on 7. August 2024, 12:33 by Hierophis69
The cold lines were straightforward, I had some initial problems with the hot lines. They seemed not very helpful at first, but combined with the Dutch flat constraints they resolved nicely.
on 7. August 2024, 11:39 by GorgeousNicko
Lovely puzzle. Looked impossible -wasn't (quite) :)
