18. Set Multiple Bits in 8-bit Register

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

uint8_t set_range(uint8_t reg, uint8_t start, uint8_t end) {
    // Your code here
    int mask = 0;
    /*for(uint8_t i=start ; i<=end; i++){
        mask |= (1<<i);
    }*/
    mask =  ((1 <<(end-start+1))-1)<<start;
    reg |= mask;
    return reg;
}

int main() {
    uint8_t reg, start, end;
    scanf("%hhu %hhu %hhu", &reg, &start, &end);
    printf("%u", set_range(reg, start, end));
    return 0;
}