Another interesting thing about C integers that the quiz doesn't cover is that remainder is not modulus. For example, in Python:

    >>: 2 % -5
    -3

But in C:

    2 % -5 == 2

If you want to use modulus in C rather than Euclidean remainder, then you have to use a function like this, which does what Python does:

    long mod(long x, long y) {
      if (y == -1) return 0;
      return x - y * (x / y - (x % y && (x ^ y) < 0));
    }