Originally Posted by
laserlight
That's because int is presumably 4 bytes and thus 32 bits on your system. The online calculator you used set it as 16 bits instead.
That would be a general issue if you choose to go with option 2: the representation of the negative integer necessarily depends on how many bits you intend to represent. (That's kind of true for positive integers too, but I guess it is more natural for humans familiar with the Hindu-Arabic numeral system to omit leading zeroes.)