45. Serialized Data Buffer

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

void build_packet(uint8_t command, uint16_t value, uint8_t status, uint32_t checksum) {
    uint8_t buffer[10];
    uint8_t *ptr = buffer;

    // Header
    *ptr = 0xA5;
    ptr++;

    // Command
    *ptr = command;
    ptr++;

    // Value (2 bytes)
    *ptr = value & 0xFF;  // low byte
    ptr++;
    *ptr = (value >> 8) & 0xFF; //high
    ptr++;

    // Status
    *ptr = status;
    ptr++;

    // Checksum (4 bytes)
    *ptr = checksum & 0xFF;
    ptr++;
    *ptr = (checksum >> 8) & 0xFF;
    ptr++;
    *ptr = (checksum >> 16) & 0xFF;
    ptr++;
    *ptr = (checksum >> 24) & 0xFF;
    ptr++;

    *ptr = 0x5A;

    for (int i = 0; i < 10 ; i++)
        printf("%d ", buffer[i]);
}

int main() {
    uint8_t cmd, status;
    uint16_t val;
    uint32_t crc;

    scanf("%hhu %hu %hhu %u", &cmd, &val, &status, &crc);
    build_packet(cmd, val, status, crc);
    return 0;
}