3 ms·

1110 + 1111 = 1101 1101 - 1110 = 1111 1101 - 1111 = 1110 Overflow doesn't matter if you just want to swap.

• Sacho 10y ago
  (Assuming two's complement arithmetic, as amelius pointed out - I don't know if all programming languages and platforms use it)
• mcintyre1994 10y ago
  That's a really smart observation I hadn't made, thanks for explaining!