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 result = 0;

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

    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;
}