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

    uint32_t mask = 0;
    int i = 0;

#if 0
    while(i < len)
    {
        mask = (mask | (1 << (pos+i)));
        i++;
    }
#endif

    mask = ((1 << 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