30. Count Set Bits in an Integer

#include <stdio.h>

int countSetBits(unsigned int n) {
    unsigned int set_bit_count = 0;
    unsigned int size = sizeof(n) * 8;
    for(unsigned int i = 0; i < size; i++) {
        if (n & (1U << i)) {
            set_bit_count++;
        }
    }
    return set_bit_count;
}

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