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 length = end - start + 1;        // How many bits to set
    unsigned char mask = (1 << length) - 1; // Create mask of ones
    mask <<= start;                      // Shift into position
    return reg | mask;                   // Set those bits
    
}

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