30. Count Set Bits in an Integer

#include <stdio.h>

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

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