Extract the Nibble from an 8-bit Register

Code

#include <stdio.h>

unsigned char extractNibble(unsigned char reg, int pos) {
    // Write your code here
    int lower_nibble = 0x0f;
    int upper_nibble = 0xf0;

    if(pos){
        reg = reg & upper_nibble;
        return reg>>4;

    }
    else
    {
        return reg & lower_nibble;
    }
}

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

Solving Approach