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 nibble;

    if (pos == 0 || pos == 1)
    {
        if (pos == 0)
            nibble = reg & 0x0F;
        else
            nibble = reg >> 4;
    }
    else
        return 0;

    return nibble;
}

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