Extract a Bit Field from a 32-bit Register

Code

#include <stdio.h>
#include <stdint.h>

uint32_t extract_field(uint32_t reg, uint8_t pos, uint8_t len) {
    uint32_t res = 0;
    reg = reg >> pos    ;     // sửa 1
    for(int i = 0; i < len; i++) {
        int bit = (reg >> i) & 1;
        res |= (bit << i);   // sửa 2
    }
    return res;
}


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;
}

Solving Approach