30. Count Set Bits in an Integer

#include <stdio.h>

int countSetBits(unsigned int n) {
    // Write your code here
    unsigned int reg=n;
    int ans=0;
    while(reg!=0){
        if((reg&1)!=0){
         ans++;
        }
        reg=reg>>1;
    }
    return ans;
}

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