Count Non-Set (0) Bits in a 32-bit Integer in c

🧮 Count Non-Set (0) Bits in a 32-bit Integer

#include <stdio.h>

int main()
{
    unsigned int num;
    int count = 0;

    // Read input from user
    printf("Enter the number : ");
    scanf("%u", &num);

    // Loop through all 32 bits
    for (int i = 0; i < 32; i++)
    {
        if ((num & (1 << i)) == 0)
        {
            count++;
        }
    }

    // Output result
    printf("The count of non set bits is %d\n", count);

    return 0;
}
  

📘 Explanation:

🔹 The program loops over each bit of a 32-bit unsigned integer using a bitwise AND operation.
🔹 If a bit is 0, it increments the `count` of non-set bits.
🔹 Works for any unsigned integer in the 32-bit range.

🧪 Sample Output:

Enter the number : 10
The count of non set bits is 30
    

🏷️ Keywords:

C program to count 0 bits, count unset bits, bitwise logic, 32-bit integer, technical interview question, C beginner practice