Logic Masters Deutschland e.V.

Shards

(Published on 31. May 2022, 12:00 by grkles)

This is an approximation of my thought process while setting this puzzle, which you might find informative:
  1. I wonder how I can force a set of negative digits with arrows...
  2. Turns out I can. Hmm... how many more arrows would it take to make this unique?
  3. Oh.... oh this is pure evil. And it has a logical solve path, too. Time to post it!

Basically, what I'm saying is: I'm sorry in advance.


Normal sudoku rules apply.

Arrows: Digits along an arrow must sum to the digit in the associated circle, and may repeat if allowed by other rules. However, 5 of the digits from 1-9 are treated as negative wherever they appear in the grid, for the purposes of determining arrow relationships (i.e., on arrows and arrow circles). The solver must determine which five digits are negative.

Solve online:

Solution code: The set of negative digits in order, followed by row 5 (14 digits, no spaces).

Last changed on -

Solved by Niverio, Andrewsarchus, deltameth, JayForty, laky, Vebby, polar, bigger, cdwg2000, fjam, amarins, rmn, kolot, SuWi, purpl, Muhammad, OGRussHood, Playmaker6174, DarthParadox, Jonhy, wpolly, pkp, x_x_eloise_x_x, teeandmo
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Comments

on 4. March 2023, 12:27 by Playmaker6174
I don't think I have much things to say here besides what the other comments had said: easy determination on the set of digits at first, then a pure mental exercise on each clue in the puzzle. Luckily I used the grand design for this specific one so I wouldn't be so lost after certain points x)

on 8. June 2022, 05:13 by kolot
That was a very crazy puzzle!

on 1. June 2022, 21:27 by bigger
it is a grind. I guess since I'm not familiar with the sum of the combo, I have to list all the combo and eliminate one by one

Last changed on 1. June 2022, 13:38

on 1. June 2022, 13:37 by Vebby
Very hard. I enjoyed the logic to figure out the negative digits. After that I relied on copious note-taking to make progress (mathcha.io is a very nice tool for notes, especially mathematical). Would love to try more puzzles with this rule-set but smoother solve paths. Thanks for the challenge grkles! :)

on 1. June 2022, 11:19 by laky
I want to know the logical solve path

on 31. May 2022, 20:41 by JayForty
Brutal and evil. Redeeming factor was the quick assistance I got when I accidentally broke the puzzle at the very end. :D Thank you for this original and clever challenge!

on 31. May 2022, 20:26 by deltameth
Totally agree with previous comments. You quickly find out which digits are negative and think that you are half way in. But this is just a bait to torture you for the next two hours.
Anyway, I'm glad that I finally made it. My applaus to the author for a very remarkable puzzle.

on 31. May 2022, 20:03 by Andrewsarchus
Great puzzle!
I applaud your evilness!

on 31. May 2022, 12:35 by Niverio
I am so glad I solved this puzzle when it first came out so that I don't need to re-solve. The first deductions bait you in, and then the rest is more grindy than climbing Everest.
Grkles, you are evil.

Difficulty:5
Rating:91 %
Solved:24 times
Observed:5 times
ID:000A2J

Variant combination Online solving tool

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Solution code:

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