Logic Masters Deutschland e.V.

clover's expert math class

(Published on 13. July 2021, 23:09 by Qodec)

Dedicated to my kind friend. I thought I read somewhere that she likes this genre, and so I tried for one.

Normal sudoku rules apply.

The grid contains some white circles that have a number and a math operation. If you apply that operation to each pair of diagonally opposite numbers touching the circle, then you'll get the number in the circle as your result both times. (See below for examples.)

A circle can also contain a question mark rather than a result. In that case the result is the same for both pairs of digits but must be deduced by the solver.

If a circle does not contain a math operation, the digit(s) that appear in the circle must appear somewhere in the four cells adjacent to the circle. (These are normal quadruple clues.)

You can play this puzzle online using the CTC app: https://tinyurl.com/yjrpmzf6 or on f-puzzles: https://f-puzzles.com/?id=yjylogbx.

- Examples -

If you have a circle with "7+" in it, both pairs of diagonally opposite digits touching that circle must sum to 7. One valid example would be 1, 5, 6, 2 going around the circle clockwise (or counterclockwise). A circle with "?x" in it could be 1, 3, 9, 3 for example (1x9 = 3x3 = 9), or 4, 3, 6, 8 (4x6 = 3x8 = 24).

The digits can be in any order. A "1-" for example behaves exactly as if there were two white kropki dots between both cells of each pair (NW-SE, SW-NE).

For the "?/" clue, the result of dividing both digits of each pair touching that circle could be 1, or even a fraction such as ¾ (three quarters).

Some valid arrangements:

Enjoy!

Solution code: Rows 5 and 9. I.e. the 9 digits in row 5 from left to right, followed by the 9 digits in row 9 from left to right, for example: 123456789123456789

Last changed on on 14. July 2021, 12:05

Solved by Arka Badarka, PotatoHead21, gameface, abed hawila, mandourin, Playmaker6174, PixelPlucker, PulverizingPancake, bakpao, SudokuExplorer, udukos, bharpe, soroush, polar, smckinley, Grothenlace, Kilonum, ... koba1917, Duarte, matiasv5, juventino188, cfop, KuulGryphun, Vebby, michaal94, nordloc, twobear, Uhu, OGRussHood, zhergan, picoton, Chishiri, CaptZebraCakes, Bellsita, misko, ManuH, Bobbobert
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Comments

on 18. July 2021, 22:22 by Qodec
Thanks everyone for the wonderful feedback!

Last changed on 18. July 2021, 22:12

on 18. July 2021, 18:27 by SKORP17
die Zahlen in den Quadruples dürfen doch doppelt vorkommen?

@SKORP17 Ja dürfen sie (wenn normale Sudoku Regeln es zulassen).

Last changed on 18. July 2021, 22:20

on 17. July 2021, 08:30 by Phistomefel
It was astounding for me to see how strong operator circles are, since only so few of them can already force a unique solution. Thank you for setting this elegant puzzle, Qodec!

@Phistomefel It surprised me as well. Makes it a fun constraint to work with. And, you're welcome!

on 14. July 2021, 23:14 by udukos
Wonderful puzzle!

on 14. July 2021, 21:47 by SudokuExplorer
The solve path is really elegant, thanks!

on 14. July 2021, 19:13 by PixelPlucker
Ridiculously brilliant.

Last changed on 14. July 2021, 23:32

on 14. July 2021, 17:23 by Playmaker6174
My goodness I wasn't preparing for that many knowledge bombs in this puzzle, so beautiful yet so tricky. Thanks for another incredible and brilliant puzzle :)

[If you're reading this comment Simon & Mark, I can assure you that the puzzle is just pure genius works.]

on 14. July 2021, 14:46 by mandourin
True sorcery.

Last changed on 14. July 2021, 14:04

on 14. July 2021, 12:47 by abed hawila
The choice and placement of the clues are just exceptional and the puzzle is just brilliant. Very clever construction, Loved it, thanks Qodec!

@abed hawila Thank you!

on 14. July 2021, 12:05 by Qodec
Added examples to clarify ruleset.

on 14. July 2021, 08:21 by gameface
Loved solving this one.

Last changed on 14. July 2021, 12:06

on 14. July 2021, 01:42 by SudokuExplorer
@Qodec: Since subtraction and division are not commutative operations, you might want to state whether there is a specific order [eg topmost cell minus (or divided by) bottommost cell] or not [larger number minus (or divided by) smaller number].

Also, it is worth mentioning whether or not a result (?) has to be an integer or is allowed to be any valid rational number.

@SudokuExplorer Done! Thanks for the suggestions!

Difficulty:4
Rating:99 %
Solved:52 times
Observed:6 times
ID:0006YC

Puzzle variant Arithmetic puzzle

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Solution code:

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