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

# Introduction

In this question, every element appears an even number of times except for one element, which appears an odd number of times. The element that appears an odd number of times is our answer.

Let's see how to achieve this using the XOR operator.

# Problem statement
We need to write a program to find the element, which is repeated odd number of times.

```
Input: {4, 3, 3, 4, 4, 4, 5, 3, 5}
 
Output: 3
```

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

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

For `n` numbers, the same 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.

In this lesson, we will learn about an odd occurring element in the given input array. 

Find Odd Occurring Element

In this lesson, we will learn about an odd occurring element in the given input array.

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

Find Odd Occurring Element

Introduction

Problem statement

Concepts