Set Specific Bits in a 32-bit Register

Code

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

uint32_t set_bits(uint32_t reg, uint8_t pos, uint8_t len) {
    //Your code here
    /*
    for (uint8_t n = 0; n < len; n++) {
        reg |= (1 << pos);
        pos++;
    }
    */
    uint32_t mask = ((1U << len) - 1) << pos;
    return reg | mask;
}

int main() {
    uint32_t reg;
    uint8_t pos, len;
    scanf("%u %hhu %hhu", &reg, &pos, &len);
    printf("%u", set_bits(reg, pos, len));
    return 0;
}

Solving Approach