I cant figure this out "Note that any element of the array can only be counted in one Perfect Pair. Also if there are multiple correct answers, return the smallest one.", I dont understant why the answer to the following case is 10 and not 15.

kata.Pairwise(new int[]{0, 0, 0, 0, 1, 1},1);

if in the previous case the answer is 10, then what is the answer of the following:

kata.Pairwise(new int[]{0, 0, 1, 1, 0, 0},1);

The same thing happened to me, you have to validate when the rank goes through 0, for example (-5 to 1), (-1 to 4), (4 to -2), (7 to -4), in all that cases you dont have to count the rank 0.