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) 
{
    int num=0;
    if(len<=4)
    {
        num =(reg>>pos)&0x0f;
    }
    else if(len>4)
    {
        num =(reg>>pos)&0xff;
    }
    return num;
}

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;
}