25. Pack Multiple Fields into a 16-bit Control Register

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

uint16_t pack_register(uint8_t mode, uint8_t speed, uint8_t status) {
    // Your logic here
    uint16_t reg;

    for (int i = 0; i < 16; i++){
        if (i <= 2){
            if (mode & (1<<i)){
                reg |= (1<<i);
            }
        } else if (3 <= i && i <= 7){
            if (speed & (1<<(i-3))){
                reg |= (1<<i);
            }
        } else if (10 <= i && i <= 15){
            if (status & (1<<(i-10))){
                reg |= (1<<i);
            }
        }
    }

    return reg;
}

int main() {
    uint8_t mode, speed, status;
    scanf("%hhu %hhu %hhu", &mode, &speed, &status);

    uint16_t reg = pack_register(mode, speed, status);
    printf("%u", reg);
    return 0;
}