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
    uint8_t mask = 0;

    // find binary mask
    for(int i = 0;i <= (end - start);i++){
        mask |= (1 << i); 
    }
    reg &= ~(mask << start); // clear the bits
    reg |= (mask << start); // new values = mask, (mask & mask) = 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;
}