Extract the Nibble from an 8-bit Register

Code

#include <stdio.h>

unsigned char extractNibble(unsigned char reg, int pos) {
    // Write your code here
    if(pos==0)
    {
         unsigned int mask=0x0f;
        reg=reg&mask;
        return reg;
    }
    else
    {
        reg=reg>>4;
        unsigned int mask=0x0f;
        reg=reg&mask;
        return reg;
    }
}

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

Solving Approach