What is an efficient way to find disjoint elements in two arrays?

Question

I have the following arrays:

A = [1,2,3,4,5]
B = [2,6,7,1]

I want to find the disjoint elements, which are as follows:

output = [3,4,5,6,7]

I was able to achieve this as follows,

output = A + B - (A & B)

but it is inefficient, as I'm adding two arrays and then removing common elements. It is similar to finding non-intersecting elements. Can I do it better than this? If so, how?

Answer 1

How about just selecting elements in A not in B and elements in B not in A.

(A - B) + (B - A)