Optimization of a nested loop

Hello guys I wrote the following code, but it takes ages to complete. Could you please help me optimizing it? A and B are matrixes

for i=1:length(A)
    for j=1:length(B)
        CCI = CCI + heaviside(norm(A(i,:)-B(j,:)));
    end
end

Thanks

Answer 1

Not necessarily faster, prettier, less confusing or better in any way with the exception of being on one line and containing the awesomeness that is bsxfun:

CCI2 = sum(sum(heaviside(sqrt(sum(bsxfun(@minus,A,reshape(B',1,size(B,2),size(B,1))).^2,2)))))

Answer 2

other variant

CCI = (nnz(any(bsxfun(@minus,A,reshape(B',1,size(B,2),[])),2)) + size(A,1)*size(B,1))/2;