27. Extract Bit Field from 16-bit Register

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

uint8_t extract_field(uint16_t reg) {
    uint8_t b=0,a=0;
    int c=0;
    for(int i=4;i<=8;i++){
        b=1&(reg>>i);
        a=a|(b<<c);
        c++;
    }
    return a;
}

int main() {
    uint16_t reg;
    scanf("%hx", &reg);
    printf("%u", extract_field(reg));
    return 0;
}