Packet Layout Using Union with Struct

Code

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

typedef union {
    struct {
        uint8_t start;
        uint8_t command;
        uint16_t data;
        uint8_t crc;
        uint8_t end;
    } fields;
    uint8_t raw[6];
} Packet;

// Fill struct fields and print raw bytes
void build_and_print_packet(uint8_t s, uint8_t c, uint16_t d, uint8_t crc, uint8_t e) {
    // Your logic here
    Packet pac;
    pac.raw[0]=s;
    pac.raw[1]=c;
    pac.raw[2]=d|0XFF000000;
    pac.raw[3]=d>>8;
    pac.raw[4]=crc;
    pac.raw[5]=e;
    printf("%u ",pac.raw[0]);
    printf("%u ",pac.raw[1]);
    printf("%u ",pac.raw[2]);
    printf("%u ",pac.raw[3]);
    printf("%u ",pac.raw[4]);
    printf("%u",pac.raw[5]);
}

int main() {
    uint8_t s, c, crc, e;
    uint16_t d;
    scanf("%hhu %hhu %hu %hhu %hhu", &s, &c, &d, &crc, &e);
    build_and_print_packet(s, c, d, crc, e);
    return 0;
}

Solving Approach

simple union member accessing using this and bit shifting