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 =0;
    /*for(int i=0;i<len;i++){
        mask =mask | (1<<(pos+i));
    }*/
    mask = ((1<<len)-1)<<pos;
    reg = reg & (mask);
    reg>>=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;
}