34. Count Set Bits in an 8-bit Register

#include <stdio.h>
#include <stdint.h>

uint8_t count_set_bits(uint8_t reg) 
{
    uint8_t ones_counter = 0;
    while(reg > 0)
    {
        reg &= (reg -1u);
        ones_counter++;
    }
    return ones_counter; 
}

int main() {
    uint8_t reg;
    scanf("%hhu", &reg);
    printf("%u", count_set_bits(reg));
    return 0;
}