This is a variant of a sandwich sudoku puzzle, involving 1-9 sandwiches and 2-8 sandwiches.
Fill the grid with numbers from 1 to 9, so that every row, column, and 3x3 box contains each of the 9 numbers exactly once. A number next to a row or column equals the sum of the numbers between the 1 and the 9 in that row or column, and it also equals the sum of the numbers between the 2 and the 8 in that row or column.
If there's no number next to a row or column, then the sums between 1 and 9 and between 2 and 8 can have any values; they may or may not be equal to each other.
The puzzle is available on Penpa.
Solution code: Row 7 and row 8.
on 11. October 2020, 20:03 by Nylimb
Added penpa link.
on 21. July 2020, 19:06 by cam
That was really excellent!
on 7. July 2020, 20:53 by Workout9
The beauty of the Numbers :)