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, input a number and check if the $k^{th}$ bit is set or not.

# Problem statement

Given two positive integers n and k check whether the bit at position k, from the right in the binary representation of n, is set `1` or unset `0`.

```
Input: n = 5, k = 1 
 
Output: true
```
```
Input: n = 10, k = 2
 
Output: true
```
```
Input: n = 10, k = 1 
 
Output: false
```

# Algorithm
* If `n == 0` return;
* Initialize `k = 1`
* Loop
   * If `(n & (1 << (k - 1))) == 0` increment the pointer `k`
   * Else return `k`


# Code

Here is the logic for this solution.

In this lesson, we try to find a bit in the binary representation of a number at the kth position and check if it is set/un-set.

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

Check If Kth Bit Is Set/Unset

Introduction

Problem statement

Algorithm