Convert 0 to 1 and Vice Versa

Question

I was asked in an interview : how to convert 0 to 1 and 1 to 0. I answered :

1. Simple if and switch
2. Bit flipping.

Are there any other approach?

Answer 1

Simple arithmetic:

x = 1 - x;

Actually, there are an infinite number of polynomials that will map 1 to 0 and vice versa. For example:

x = x * x * x * x * x - x * x * x * x + x * x - 2 * x + 1;