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
    // create mask:
    // uint32_t mask = 0x00000000;
    // for (uint8_t i=pos; i<pos+len; i++){
    //     mask |=(1<<i);
    // } 
    uint32_t mask = ( (1U <<len) -1 ) << pos;
    // apply mask 
    reg |= mask;
    return reg;
}

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