Question

Wnte the definition of a member function AddPac ket() for a class QUEUE in C++, to remove/delete a Packet from a dynamically allocated QUEUE of Packets' considering the following code is already written as a part of the program.

struct Packet
{
   int PID;
   char Address[20];
   Packet *LINK;
};

class QUEUE
{
    Packet *Front, *Rear;
public:
    QUEUE(){Front=NULL;Rear=NULL;}
    void AddPacket();
    void DeletePacket();
    ~QUEUE();
};

Answer 1

void QUEUE::AddPacket()
{ 
     Packet *temp = new Packet;
     if(temp==NULL)
     {
         cout<<“Overflow”<<endl;
     }
     cout<< “Enter PID”;
     cin >> temp->PID;
     int n = temp->PID;
     temp -> Link=NULL;
     // for first node
     if(Front == NULL)
     {
        Front = Rear = temp;
     }
     else
     {
        Rear->Link = temp;
        Rear = temp;
     }
     cout<< n << "has been inserted successfully."<<endl;
    //display
    if(Front= =NULL)
    {
        cout<< “Underflow.”<<endl;
        return;
    }
    else
   { 
       temp = Front;
      //will check until NULL is not found
      while(temp)
     {
           cout << temp -> PID << “ “;
           temp = temp -> Link;
     }
     cout<<endl;
   }
}

void QUEUE::DeletePacket()
{
    if(Front == NULL)
    {
        cout<< "underflow"<< endl;
        return;
    }
    cout << Front -> PID <<" is being deleted "endl;
    if (Front = = Rear) // if only one node is there
        Front = Rear = NULL;
    else
        Front = Front -> Link;
    //display
    if(Front == NULL)
   {
       cout<< "Underflow."<<endl;
       return;
   }
   else
  {
       Packet *temp=Front;
       // will check until NULL is not found
       while(temp)
      {
          cout << temp -> PID << "";
          temp = temp -> Link;
      }
      cout<<endl;
  }
}