Elcano (2nd Gift for Flash Groudon)
(Published on 9. January 2025, 18:08 by the_cogito)
Of course, this draws inspiration from Jörmungandr. The puzzle is probably not 5/5 in terms of raw difficulty, and a lot of effort has been made to make individual steps flow decently, but it's arguably 5/5 in sheer time necessary to solve it. Enjoy!
The rules:
- The grid contains 5 overlapping 9x9 Sudoku grids: one in each cardinal direction, and a central grid shown with dotted lines. Within each 9x9 Sudoku grid, normal Sudoku rules apply.
- Digits along a blue region sum line must have an equal sum within each region the line passes through (As a point of clarity, the grid contains two lines, each with its own respective sum).
- If a region sum line passes through a region multiple times, each pass-through is treated separately.
Solve on SudokuPad
Solve on Penpa+
Solution code: Column 5 of the central Sudoku grid (9 digits, no spaces)
Comments
on 15. February 2025, 20:03 by 8th
Incredible puzzle, my longest solve to date yet at 605m37s, incredibly satisfying, I never felt frustrated, only joyous at every breakthrough both big and small! <3
on 11. January 2025, 18:13 by dumediat
Ambitious and fantastic!
on 11. January 2025, 18:05 by askaksaksask
This did take a while to fully mark, but there were no dead spots in the solve and it was quite fun! Thank you!
on 10. January 2025, 18:24 by Snookerfan
Beautiful puzzle! Indeed not too hard, but a really long and enjoyable ride. Thank you
on 10. January 2025, 16:08 by skuntsel
What an enjoyable time and what a monstrously long and clever puzzle! You have to keep your attention sharp all the time to locate the ramifications. The actual break-in is really nice around the central box when everything starts to click in. Just amazing how it all resolves around a minor as it seems detail. Afterwards it is a long play of ping-pong around the grid that is really fascinating. Region sum line masterpiece! Thanks for setting it, the_cogito!
on 10. January 2025, 15:09 by Aspartagcus
Very enjoyable 3 hours spent on solving this one! Beautifully crafted!
on 10. January 2025, 12:27 by Piatato
Lovely! Smooth and pleasant throughout!
on 10. January 2025, 02:32 by Flash Groudon
It's amazing how smoothly this solves. Thank you again for this lovely puzzle :)
