Bitwise NOT operator returning unexpected and negative value? [duplicate]

Answer 1

In two-complement arithmetic to get a reverse number (for example for value 16 to get value -16) you need reverse each bit and add 1.

In your example, to get -16 from 16 that is represented as

00000000000000000000000000010000

you need reverse each bit. You will get

11111111111111111111111111101111

Now you must add 1 and you will get

11111111111111111111111111110000

As you can see if you add these two values, you will get 0. It proves that you did all correctly.