Compute the complement of a set of indices in a known range

I want to compute the complement of a set C. The elements are indices in the range 1 to K. Is the best/fastest/simplest way to go around this is using

    C = setdiff(A,B)

or since I know they are not arbitrary sets of numbers, is there a better way to go around in MATLAB?

[Azzi Abdelmalek]

What do you mean? can you clarify what "not arbitrary sets of numbers" means, with a small example

[Brando Miranda]

I just have susbets from a set of indices. So A Union B is the same as 1 to K. So the sets A and B are always in a predefined set of indices 1 to K. An example would be A=[1,2,5] and B=[3,4].

But I wouldn't get as input A=[0.1, 0.2], B = [0.5] since that is not a valid index range in question.

Answer 1

[Dave Behera]

Your approach with setdiff seems to be the best way because it is the simplest. I recommend you to use it.