30. Count Set Bits in an Integer

#include <stdio.h>

int countSetBits(unsigned int n) {
    // Write your code here
    unsigned int size =  sizeof (n);
    unsigned int k = 0;
    unsigned int count = 0;
    while (k < size*8){
        unsigned tmp = (n >> k) & (1U);
        if (tmp == 1){
            count ++;
        }
        k++;
    }
    return count;
}

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