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 two numbers and swap them without using the swapping logic.

# Problem statement
We need to write a program to swap two numbers.

```
Input: a = 10, b = 121
 
Output: a = 121, b = 10
```

# Solution

We can make use of XOR to swap two values. You will find the solution below:

class SwapTwoNumbers {
    public static void main(String[] args) {

        int a = 10, b = 121;
        a = a ^ b;
        b = b ^ a;
        a = a ^ b;

        System.out.println("Finally, after swapping; a = " + a + " , b = " + b);
    }
}

Java

def swap_nums(a,b):
    a=a^b
    b=b^a
    a=a^b
    print("Finally, after swapping a =", a, ",b =", b)

a=10
b=121
swap_nums(a,b)

Python

JavaScript

#include <iostream>

using namespace std;

int main() {
    int a = 10, b = 121;
    a = a ^ b;
    b = b ^ a;
    a = a ^ b;
    cout << "Finally, after swapping; a= " << a << " , b = " << b;
    return 0;
}

export const SwapTwoNumbers = (a: number, b: number): void => {
    a = a ^ b;
    b = b ^ a;
    a = a ^ b;

    console.log(`Finally, after swapping; a = ${a} , b = ${b}`)
}

const a: number = 10;
const b: number = 121;

SwapTwoNumbers(a, b);


TypeScript

# Complexity analysis

**Time Complexity:** We are not running a loop or scaling the inputs. The inputs never change. So the operation takes a single unit of time, which is $O(1)$.

**Space Complexity:** We didn't create an extra memory for this. So, the space complexity is $O(1)$.

In this lesson, we make use of the XOR operator to swap the values of two inputs.

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

Swap Two Numbers

Introduction

Problem statement

Solution

Complexity analysis