I noticed that in the nerd snipes website, double arrow are not yet included, perhaps we should fill in that section this year!
Normal sudoku rules apply.
Double Arrow: The sum of the two endpoint circles must equal the sum of the digits along the connecting line.
Puzzle:
With allowing 1 diagonal DA, I got 16 circles by using 19 double arrows. What is the lowest possible number?
Solution code: Box 8 please.