C Introduction to Programming It is short and simple practic

C++ Introduction to Programming

It is short and simple practice.

Classes: members and methods

Please solve #5

#include<iostream>

#include<vector>

..

using namespace std;

5. Consider an application that maintained \"mailboxes\" for users. Each user has their own mailbox, and each mailbox can hold any number of (string) messages. Sketch a set of class definitions that could be used to represent users, mailboxes, and messages. YOUR ANSWER HERE

Solution

A mailbox is an abstract date type capable of containing a number of messages of variable size defined by the following C/C++ structure:–

struct msg {
   int iFrom; /* who sent message (0 .. number-of-threads) */
   int type; /* its type */
   int num; /* number of items in payload (0 .. MAXPAYLOAD) */
   long payload[MAXPAYLOAD]; /* payload, an array of long */
};

SendMsg(msg &Msg)  // Msg is reference to message to be sent;
                   // blocks if mailbox is full
RecvMsg(msg &Msg)  // Msg is reference to area to store
                  // received message; blocks if mailbox
                   // is empty

Mailbox(int size)  // Constructor for mailbox of size bytes
~Mailbox()         // Destructor of mailbox

SendMsg(int iTo, struct msg *pMsg)      // msg as ptr
/* iTo - mailbox to send to */
/* pMsg - message to be sent */

RecvMsg(int iFrom, struct msg *pMsg) // msg as ptr
/* iFrom - mailbox from which to get messages */
/* pMsg - message structure to fill with received message */

CreateMailbox(int size) // routine to create and initialize
DestroyMailbox() // routine to deallocate and destroy