Icing disaster (Region sum lines/X-sums)
(Published on 30. June 2023, 22:38 by dumediat)
This is a puzzle that I created for Derektionary's (djorr's) birthday, which they encouraged me to share with all of you. Ratings, comments, and feedback are much appreciated! Please feel free to reach out to me on Discord if you have any comments or questions. Please also feel free to try my other puzzles here.
Edit: This puzzle was featured on CTC! Click here if you would like to watch Simon's solve.
Rules:
- Normal sudoku rules apply.
- Region sum lines: Digits on a blue line must have an equal sum within each region it passes through, regardless of how many times the line exits and re-enters a region. The area outside the grid is considered one region for purposes of this rule. Different lines may have different sums.
- X-sums: Numbers outside the grid give the sum of the first N digits in their respective row or column, where N is the digit nearest the clue (inside the grid).
To be clear: This puzzle uses the "old" region sum lines rules, which affects how the lines work in boxes 1 and 7 specifically. The following statements describe how these lines must be interpreted (rows/columns 0 and 10 indicate cells outside the 9x9 grid):
- Box 1: r0c1 + r1c0 = r1c2 + r1c3 + r2c1 + r3c1 + r3c2
- Box 7: r8c0 + r10c3 = r7c1 + r8c1 + r9c1 + r9c2
Penpa+ (recommended for note taking): https://tinyurl.com/23srx4rh
SudokuPad: https://tinyurl.com/4w5w9veu
Solution code: Row 7 followed by column 2 of the 9x9 grid (18 digits)
Comments
on 16. August 2023, 19:56 by damasosos92
Brilliant!!
on 22. July 2023, 18:23 by Silverbyte
This took me quite a long time but the logic was truly excellent! Loved how tricky this was while still having a smooth solve path
on 12. July 2023, 14:15 by Bankey
Gorgeous puzzle. Thanks, @ dumediat :).
on 12. July 2023, 07:41 by ddx01
Loved this one! Thank you, dumediat! ^_^
on 11. July 2023, 20:12 by glum_hippo
Happy belated birthday, Derektionary! Nice puzzle!!!!!
on 11. July 2023, 18:18 by dumediat
Added link to CTC's solve.
on 3. July 2023, 22:14 by dumediat
Updated links so solution checker works in SudokuPad and rules clarification is included.
on 2. July 2023, 17:09 by madhupt
What a brilliant puzzle! Really satisfying to have completed it. It is really wonderful how the two conditions interact to guide on the solve path. Thanks a lot for sharing.
>>dumediat: You're welcome! I'm glad you enjoyed it, and thank you very much for the kind words!
on 1. July 2023, 20:15 by bansalsaab
Awesome. Thanks for setting it.
>>dumediat: You're welcome, I'm glad you enjoyed it!
on 1. July 2023, 12:11 by Piatato
Awesome puzzle!
>>dumediat: Thank you! :)
on 1. July 2023, 12:04 by marcmees
quite some search, but enough interactions not to get lost. Very nice. Thanks.
>>dumediat: I'm glad you enjoyed it!
on 1. July 2023, 11:43 by Elliott810
Absolutely brilliant puzzle! Take a bow and thanks:)
>>dumediat: Thank you so much! :D
on 1. July 2023, 00:56 by Myxo
Wonderful puzzle! Some really fun geometry in this one.
