Bits, Bytes, Building With Binary
https://www.youtube.com/watch?v=NLKQEOgBAnw
Practice with bit operators (|,&,^, >)
Knowledge of binary number system and bit manipulation is less important in coding interviews as most Software Engineers do not have to deal with bits, which is more commonly used when dealing with lower level systems and programming languages. They are still asked sometimes, so you should at least still know how to convert a number from decimal form into binary form, and vice versa, in your chosen programming language.
Questions involving binary representations and bitwise operations are asked sometimes and you must be absolutely familiar with how to convert a number from decimal form into binary form (and vice versa) in your chosen programming language.
Some helpful utility snippets:
| Technique | Code |
|---|---|
| Test kth bit is set | num & (1 << k) != 0. |
| Set kth bit | num |
| Turn off kth bit | num &= ~(1 << k). |
| Toggle the kth bit | num ^= (1 << k). |
| Multiply by 2^k | num << k |
| Divide by 2^k | num >> k |
| Check if a number is a power of 2 | (num & num - 1) == 0 or (num & (-num)) == num |
| Swapping two variables | num1 ^= num2; num2 ^= num1; num1 ^= num2 |