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

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

#define SET_MODE(x) ((x&0x7)<<0)
#define SET_SPEED(x) ((x&0x1F)<<3)
#define SET_STATUS(x) ((x&0x3F)<<10)

uint16_t pack_register(uint8_t mode, uint8_t speed, uint8_t status) {
    // Your logic here
    uint16_t reg=0;
    if (mode>7) mode=7;
    if (speed>31) speed=31;
    if (status>63) status=63;
    reg|= ((SET_MODE(mode))|(SET_SPEED(speed))|SET_STATUS(status));
    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;
}