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) {
    // Your code here
    uint32_t cur_val_at_pos = reg >> pos;
    uint32_t extracted_bits = 0;
    uint32_t cur_bit_pos = 0;
    while(len) {
        extracted_bits |= (cur_val_at_pos & 1) << cur_bit_pos++;
        cur_val_at_pos >>= 1;
        len--;
    }
    return extracted_bits;
}

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;
}