17. Extract the Nibble from an 8-bit Register

#include <stdio.h>

unsigned char extractNibble(unsigned char reg, int pos) {
    if (pos == 0) {
        // Extract lower nibble (bits 0–3)
        return reg & 0x0F;
    } else {
        // Extract upper nibble (bits 4–7)
        return (reg >> 4) & 0x0F;
    }
}

int main() {
    unsigned char reg;
    int pos;

    // Read the byte and nibble position (0 for lower, 1 for upper)
    scanf("%hhu %d", &reg, &pos);

    // Print the extracted nibble as integer
    printf("%d\n", extractNibble(reg, pos));

    return 0;
}