Intersectionality
(Published on 22. November 2021, 00:21 by Jay Dyer)
Intersectionality
Rules:
1. Standard: Normal sudoku rules apply.
2. Diagonal: Digits may not repeat on either main diagonal.
3. Anti-knight: Cells separated by a knight's move must contain different digits.
4. Killer: Digits in a cage must sum to the clue in the top left corner (if given). Digits may not repeat within a cage.
Hint:
Question: Given Aad's theorem, what happens when a digit appears in two adjacent 4-cell cages?
Answer: No digit can appear more than twice in the larger side of the Aad set (due to the smaller side containing no repeats), so if a digit appears in two adjacent 4-cell cages, it cannot appear in the unnumbered cage between them. Thus they cannot share more than two digits.
Solution code: Rows 3 and 7 (18 digits, no spaces or commas)
Comments
on 22. November 2021, 22:47 by Jay Dyer
Added some hints.
