30. Count Set Bits in an Integer

#include <stdio.h>

int countSetBits(unsigned int n) {
    int set_bits = 0;
    int num_bits = 8 * sizeof(n);
    int i;
    for(i = 0; i < num_bits; i++){
        if(n & (0x1 << i)){
            set_bits++;
        }
    }
    return set_bits;
}

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