Primescraper Sudoku
(Published on 14. August 2020, 22:07 by SenatorGronk)
I think this puzzle may be unpleasantly difficult -- like I spent too much time wondering if I could that I didn't stop to think if I should. There absolutely _is_ a logical path to completion, and I think it actually gets tougher later in the puzzle as there are more interactions between digits to consider.
That said, the break-in is pretty neat, IMHO -- you're able to nail down a lot more digits than you might expect right off the bat. Please let me know what you think. I'm happy to provide guidance if needed.
Rules
- Standard sudoku rules apply
- Each cell with a diamond contains a number equal to the number of prime numbers (2,3,5,7) that can be seen from that cell orthogonally as in a skyscraper puzzle. That is, a cell can see the number X in its row or column, as long as there are no digits larger than X between them
- The value of a given cell is irrelevant when considering how many skyscrapers it can see
- Not all possible diamonds are given
- The two cages have the same sum
Penpa link
In the example below, the 4 with a diamond can see the 5 and 7 in its column, but not the 3 which is blocked by the 5. In it's row it can see the 2 and the 5, but not the 7 which is blocked by the 9. The 2 with a diamond can see the 5 in its row and 7 in its column.
Solution code: Column 1 and Row 2 (18 digits no spaces or separators)
Comments
on 2. November 2020, 00:22 by SudokuExplorer
Wonderful! After the nice opening, it was a more attritional solve but with interesting logic. Absolutely worth solving :-)
P.S. Your diamond clues reminded me of my Multi-way skyscraper sudoku (id=0004C7), though you might find that one easier.
on 15. September 2020, 09:40 by SirWoezel
Had to restart twice because of pretty silly errors, but it was certainly worth it!
on 8. September 2020, 18:14 by StefanSch
Der Einstieg (nach den ersten 5, 6 Zahlen) war ein ganz schön dickes Brett und ich musste höllisch aufpassen, keine Fehler einzubauen.
Ansonsten war es aber eine Freude, wie sich die Lösung Stück für Stück offenbarte.
on 16. August 2020, 02:33 by Big Tiger
So ... the 2 with a diamond in your sample: Why is that not a "3" since it can see a 5, a 7, and another 7?
Oh, no, wait, I see it. It CAN'T see the 7 behind the nine. The yellowed squares were throwing me off (my fault, not yours).
on 15. August 2020, 19:27 by henrypijames
Incredibly slow going indeed, like pushing through a thick jungle.
This is the most exhausting puzzle that I've managed to solve without making a serious mistake and having to restart.
