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 value = 0;
    for(int i=pos; i<pos+len; i++){
        if(reg & (1<<i)){
            value |= (1<<i-pos);
        }
    }

    return value;
    
}

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;
}