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) {
    // Your code here
    // uint32_t mask = (((1U<< len) - 1 ) >> pos);
    // uint32_t mask = (reg >> pos) & ((1U<< len) - 1 );
    // uint32_t mask = ((1U<< len) - 1 ) >> pos;
    return ((reg >> pos) & ((1U<< len) - 1 ));
}

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