30. Count Set Bits in an Integer

#include <stdio.h>
int c=0;
int countSetBits(unsigned int n) {
    while(n){
        c += n&1;
        n >>= 1;
    }
    return c;
}

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