[mcyc]

The parent comment asked specifically about negating the finality of each state, which I addressed. As for how to actually implement complement in a regex engine, there are certainly some strategies like the one you mentioned that could be used (but the point of my comment was that just swapping final/non-final states is not a valid one).

[zeroimpl]

Ah I thought they meant flipping the finality of the final state, but I guess they said "states" so your interpretation makes more sense.