17. Extract the Nibble from an 8-bit Register

#include <stdio.h>

unsigned char extractNibble(unsigned char reg, int pos) {
    // Write your code here
    unsigned char mask;
    if(pos)
    {mask = 0b11110000;
    reg&=mask;
    reg=reg>>4;}
    else
   { mask = 0b00001111;
    reg&=mask;}
    return reg ;
}

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