17. Extract the Nibble from an 8-bit Register

#include <stdio.h>

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

    scanf("%u", &reg);   // 8-bit register value (0–255)
    scanf("%d", &pos);   // 0 = lower nibble, 1 = upper nibble

    int nibble;

    if (pos == 0) {
        nibble = reg & 0x0F;          // Extract lower nibble
    } else {
        nibble = (reg >> 4) & 0x0F;   // Extract upper nibble
    }

    printf("%d", nibble);

    return 0;
}