3 ms·

You can combine the two XORs: new_mask = old_mask XOR old_char XOR new_char count += signum(new_mask - old_mask) Where signum(x) = (x > 0) - (x < 0)

• rep_lodsb 4y ago
  If the old and new char are different, two bits will have changed state and comparing the old and new mask will have unreliable results. e.g. old mask = 011100 new mask = 001111, numerically less even though it has one more bit set
  • meindnoch 4y ago
    Dangit! I concede…