text: #ifndef PROTOCOL_H
  #define PROTOCOL_H
  
  #include <string.h>
  
  #define MAX_ROOM_SEATS  9999  // Max num of seats in the room to be reserved
  #define MAX_CLI_SEATS   99    // Max num of seats that each client can reserve
  #define WIDTH_PID       5
  #define WIDTH_XXNN      5
  #define WIDTH_SEAT      4
  
  /*
      Protocol Format - Client -> Server:
        first element is the client PID,
        followed by the num of seats,
        followed by a sequence of prefered seats
  
        Ex: 02345 0002 0456 0056 0057 0058 0059
  
            Client with PID 2345 wants 2 seats, from the 5 specified seats
   */
  #define WIDTH_REQUEST  WIDTH_PID + (MAX_CLI_SEATS + 1) * (WIDTH_SEAT + 1) + 1
  
  
   /*
      Protocol Format - Server -> Client:
        first element is number of reserved seats (or errorcode in case of error)
        followed by a sequence of the reserved Seats
  
        Ex: 0003 0123 0124 0125
  
            Server reserved 3 seats (Seat 123, Seat 124 and Seat 125)
   */
  #define WIDTH_FEEDBACK (MAX_CLI_SEATS + 1) * (WIDTH_SEAT + 1)
  
   /*
      Error Code Messages:
        Interface via Macro, stored in array with index = -errcode
   */
  char* emessages[8] = {"", "MAX", "NST", "IID", "ERR", "NAV", "FUL", "OUT"};
  #define EMSG(errcode) (errcode < 0 && errcode > -8) ? emessages[-errcode] : ""  
  
  #endif
  