The ultimate guide to bit manipulation for coding interviews. Developed by FAANG engineers, practice with real-world interview questions, and get interview-ready in just a few hours.

This course teaches bit manipulation, a powerful technique to enhance algorithmic and problem-solving skills. It is a critical topic for those preparing for coding interviews for top tech companies, startups and industry leaders. Competitive programmers can take full advantage of this course by running most of the bit-related problems in O(1) complexity.

The course will begin by educating you about the number system and its representation, decimal and binary, followed by the six bitwise operators: AND, OR, NOT, XOR, and bit-shifting (left, right).

You will receive ample practical experience working through practice problems to improve your comprehension.

Upon completing this course, you will be able to solve problems with greater efficiency and speed.

Grokking Bit Manipulation for Coding Interviews

# Solution review: Bit manipulation

We are dealing with bit manipulation and want to solve all of these problems with Bitwise operators.

## Concepts
If we take XOR of zero and a bit, it will return that bit.
> `a ^ 0 = a`

If we take XOR of two same bits, it will return 0.
> `a ^ a = 0`

For `n` numbers, the below math can be applied.

> `a ^ b ^ a = (a ^ a) ^ b  = 0 ^ b = b;`

For example: 

> `1 ^ 5 ^ 1 = (1 ^ 1) ^ 5 = 0 ^ 5 = 5;`

So, we can XOR all bits together to find the unique number.

## Algorithm

* Initialize a variable to `0`.
* Iterate over all the elements and store the value in the variable.

We try to solve the problem using a more optimal way.

Getting Started

Number Systems, Bitwise, and Binary

Bitwise AND

Bitwise OR

Bitwise NOT

Bitwise XOR

Bit Shifting - Left, Right

Bitwise LeftShift Problems

Bitwise RightShift Problems

Final Thoughts

Solution Review: Single Number

Solution review: Bit manipulation

Concepts