BIT MANIPULATION
Most computer languages have facilities to allow programmers access to the individual bits of a variable. Bit operators may appear more frequently in interviews than in day-to-day programming, so they merit a review.
Binary Two’s Complement Notation
To work with bit operators, you need to start thinking on the levels of bits. Numbers are usually internally represented in a computer in binary two’s complement notation. If you’re already familiar with binary numbers, you almost understand binary two’s complement notation because binary two’s complement notation is very similar to plain binary notation. Actually, it’s identical for positive numbers.
The only difference appears with negative numbers. (An integer usually consists of 32 or 64 bits, but to keep things simple, this example uses 8-bit integers.) In binary two’s complement notation, a positive integer such as 13 is 00001101, exactly the same as in regular binary...
