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

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

uint32_t extract_field(uint32_t reg, uint8_t pos, uint8_t len)
{
    uint32_t mask = (reg >> pos);
    uint32_t mask2 = ((1U<<len) - 1);
    uint8_t result = mask & mask2;
    return result;
}

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;
}