Normal sudoku rules apply.
Minimal between lines
Digits on a line must be between the digits in the connected circles. The difference between the circled digits must be as small as allowed by normal sudoku rules. For example, a circle in R1C2 connected with a straight line to a circle in R5C6 would have a difference of 2 because it is possible (and necessary) to repeat the same digit in all 3 spots along the line. Check out https://f-puzzles.com/?id=y2f4zy5n to see this example in action.
Clones
The grey 4x4 regions must contain the same digits in the same order and orientation.
Skyscrapers
Each digit N in the grid represents a building of height N. Numbers outside the grid indicate how many buildings can be seen from that direction in the row, with taller buildings blocking shorter buildings from being seen.
F-Puzzles link: https://f-puzzles.com/?id=yxzt7zp3
Solution code: 18 digit code: row 5 then row 6
on 31. May 2023, 02:37 by Ragna
Simon brought me on the right way...
Thank you for sharing.
on 25. May 2023, 12:58 by Fool on Hill
Lovely puzzle with some unexpected logic - enjoyed it a lot
on 3. March 2021, 12:51 by EliasKar
Amazing and definitely underrated puzzle! The logic is so original and fascinating to discover, well done!
on 6. February 2021, 12:41 by fritzdis
@brandon_bot Thanks! I have another one in testing at the moment on the CTC discord, although it has a very different feel compared to the 2 I've posted here so far.
on 6. February 2021, 11:13 by brandon_bot
I love this Minimal Between Lines ruleset. Please keep making more!
on 5. February 2021, 22:14 by fritzdis
Changed tags, updated layout
on 5. February 2021, 13:14 by StefanSch
Nice solution strategies!