34. Count Set Bits in an 8-bit Register

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

uint8_t count_set_bits(uint8_t reg) {
    int ans =0;
    // Your code here
    for(int i =0; i<8; i++){
        int mask = 1<<i;
        if(reg & mask){
            ans ++;
        }
    }
    return ans;
}

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