Extract the Nibble from an 8-bit Register

Code

#include <stdio.h>

unsigned char extractNibble(unsigned char reg, int pos) {
    // Write your code here
    unsigned char mask_nible = (1<<4)-1; // o 0x0F
    
    if (pos == 1){
        reg =(reg >> 4)& mask_nible;
        return reg;
    }else{
        reg =reg & mask_nible;
        return reg;
    }
    
    
}

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

Solving Approach