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) {
    for(int i=0;i<len;i++){
        reg|=(1<<pos);
        pos++;
    }
    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;
}

//alternate approach (2^n-1) for consecutive 1's time complexity O(1)

Solving Approach

if used 2 ^n -1 that will produce consecutive 1's