17. Extract the Nibble from an 8-bit Register

#include <stdio.h>

unsigned char extractNibble(unsigned char reg, int pos) {
    int res=0;
    for(int i=0;i<4;i++)
    {
        if(pos==0)
        {
            res=reg&0x0f;
        }
        else 
        {
            res=(reg>>4)&0x0f;
        }
    }
    return res;
}

int main() {
    unsigned char reg;
    int pos;
    scanf("%hhu %d", &reg, &pos);
    printf("%d", extractNibble(reg, pos));
    return 0;
}