30. Count Set Bits in an Integer

#include <stdio.h>

int countSetBits(unsigned int n) {
    int ONES = 0;
    while(n>0){
        ONES += (n%2);
        n/=2;
    }
    return ONES;
}

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