Count Set Bits in an Integer

Solving Approach

Brian Kernighan’s Algorithm

Code

#include <stdio.h>

int countSetBits(unsigned int n) {
    // Write your code here
    // Brian Kernighan’s Algorithm
    int count = 0;
    while(n)
    {
        // clears the lowest set bit
        n &= (n-1); 
        count++;
    }
    return count;
}

int main() {
    int n;
    scanf("%d", &n);
    printf("%d", countSetBits(n));
    return 0;
}