30. Count Set Bits in an Integer

#include <stdio.h>

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

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