[Java] Increment number without using sum operator

Here's another piece of bit magic that works on those systems where numbers are stored using 2's complement.

Since a negative number is stored using that form, and that form is obtainable by inverting all the bits then adding one, we can get the number + 1 by inverting all bits first and then flipping its sign:

n = -(~n)

This works for both negatives and positives.