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Modular Lines - a brand new sudoku variant
🕑 Added 2022-07-21 17:34:27 +0000 UTCSuper excited to share with you today two packs featuring a brand new sudoku variant - modular lines. This variation is the brainchild of two eminent math(s) professors, FullDeck and Missing A Few Cards but they (and we) are indebted to the rest of the team of setters who have contributed equally to these packs: JC Godart, jeremydover, Raumplaner and rockratzero.
How does this new variation work? Well, it's explained in the packs but, along these modular lines, every set of three sequential digits must contain a complete set of residues modulo 3, i.e. one digit from {1,4,7}, one from {2,5,8}, and one from {3,6,9}.
This post contains the base pack and is cool enough (featuring six puzzles) but, for our patrons, the next post contains the competition pack (which features no less than 18 puzzles!).
Thanks again to all six of these wonderful setters. Let us know how you get on!
Simon & Mark
Comments
Just finished - I particularly liked the last one!
João Guilherme Madeira Araújo
Really cool idea!
In some sense, yes, but the nature of modular arithmetic makes interesting things happen when you start combining with other constraints
FinnishGuy, thank you for letting us know that. We certainly didn't intend to claim undue credit. When we published the first one, we were surprised it hadn't been used before so we searched both CtC and LMD but didn't find any. We also asked on both CtC and LMD that if anyone knew of any prior puzzles using the constraint that we hadn't found, to please let us know. We're happy to give you credit for the constraint!
ProfMeow
Sort of dual to entropic lines, isn't it? The 9 digits are divided into 3 sets, A, B, and C, and each line must cycle ...ABCABC... (or ...ACBACB...). Low/medium/high and equivalence mod 3 are natural classifications, but you could also do "number of letters in the English name of the digit" or anything else you like.
Wonderful puzzles by the constructors, but this concept of modular lines is not exactly new. I published several puzzles with the construct, branded as mod3 lines late last year. All of these are published on Logic Masters Germany.
You have a confirmation that they are math(s) professors when the Sudoku document is typeset with LaTeX 🤣
