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 cnt = 0;
    /*
    while(reg > 0){
        if(reg & 0x01) cnt++;
        reg = reg >> 1;
    }
    */
    for(int i =0; i<8; i++){
        if((reg >> i) & 1) cnt++;
    }
    return cnt;
}

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