19. Extract a Bit Field from a 32-bit Register

#include <stdio.h>
#include <stdint.h>

#define MASK(length , pos)  (((1U << (length)) - 1U) << (pos))
#define EXTRACT_BIT_FIELD(reg , length , pos)  (((reg) & MASK(length , pos)) >> (pos))

uint32_t extract_field(uint32_t reg, uint8_t pos, uint8_t len) {
    // Your code here
    reg = EXTRACT_BIT_FIELD(reg, len, pos);
    return reg;
}

int main() {
    uint32_t reg;
    uint8_t pos, len;
    scanf("%u %hhu %hhu", &reg, &pos, &len);
    printf("%u", extract_field(reg, pos, len));
    return 0;
}