Count Set Bits Brian Kernighan Algorithm in DSA C - Build from Scratch

Count Set Bits using Brian Kernighan Algorithm

📖 Scenario: You are working on a simple embedded system that needs to count how many bits are set to 1 in a number. This helps in error detection and data analysis.

🎯 Goal: Build a program that counts the number of set bits (1s) in an integer using the Brian Kernighan algorithm.

📋 What You'll Learn

Create an integer variable named number with the value 29.

Create an integer variable named count initialized to 0.

Use a while loop with the condition number != 0.

Inside the loop, update number using number = number & (number - 1).

Increment count by 1 inside the loop.

Print the value of count after the loop.

💡 Why This Matters

🌍 Real World

Counting set bits is useful in error detection, cryptography, and network data analysis.

💼 Career

Understanding bitwise operations and efficient algorithms is important for embedded systems and low-level programming jobs.

1

Create the initial number variable

Create an integer variable called number and set it to 29.

DSA C

# Your code here

Hint

Use int number = 29; to create the variable.

2

Initialize the count variable

Create an integer variable called count and set it to 0.

DSA C

int number = 29;
# Your code here

Hint

Use int count = 0; to start counting from zero.

3

Apply Brian Kernighan's algorithm loop

Use a while loop with the condition number != 0. Inside the loop, update number using number = number & (number - 1) and increment count by 1.

DSA C

int number = 29;
int count = 0;

# Your code here

Hint

The loop runs until number becomes zero. Each iteration removes the rightmost set bit.

4

Print the count of set bits

Print the value of count using printf with the format "%d\n".

DSA C

int number = 29;
int count = 0;

while (number != 0) {
    number = number & (number - 1);
    count++;
}

# Your code here

Hint

Use printf("%d\n", count); to print the count.