Queue using circular array cpp program

CPP Program to implement a queue using circular array

#include<iostream.h>

#include<conio.h>

#include<stdlib.h>

#include<math.h>

const int max=10;

class queue

{ private:

          int a[max];

          int front,rear;

  public:

          queue(void);

          void addq(int);

          int delq(void);

          void display(void);

          int count(void);

};

queue::queue(void)

{       

front=rear=-1;

}

void queue::addq(int item)

{        if((front==rear+1)||(front==1&&rear==max-1))

          {        cout<<"\n Queue is full. ";

                   return;

          }

          if(front==-1)

                   front=rear=0;

          else

                   if(rear==max-1)

                             rear=0;

                   else

                             rear++;

          a[rear]=item;

}

int queue::delq()

{        int data;

          if(front==-1)

          {        cout<<"\n Queue is empty. ";

                   return NULL ;

          }

          data=a[front];

          if(front==rear)

                   front=rear=-1;

          else

                   if(front==max-1)

                             front=0;

                   else

                             front++;

                             return data;

}

void queue::display()

{        cout<<"(Front)";

          int i=front;

          if(i!=-1)

          {        while(1)

                   {        cout<<a[i]<<" ";

                             if(i==rear)

                                       break;

                             if(i==max-1)

                                       i=0;

                             else

                                       i++;

                   }

          }

          cout<<"(Rear)";

}

int queue::count(void)

{        int count=0;

          int i=front;

          if(i!=-1)

          {        while(1)

                   {        count++;

                              if(i==rear)

                                      break;

                             if(i==max-1)

                                      i=0;

                             else

                                      i++;

                   }

          }

          return count;

}

void main()

{        int c,num; char ch;

          queue q;

          while(1)

          {        clrscr();

                   cout<<"\n Perform the following Queue operations. ";

                   cout<<"\n --------------------------------------- ";

                   cout<<"\n 1.Insert elements. ";

                   cout<<"\n 2.Delete elements. ";

                   cout<<"\n 3.Display full queue content. ";

                   cout<<"\n 4.Exit from program. ";

                   do

                   {        cout<<"\n Select your Choice(1:4) : ";

                             cin>>c;

                   }

                   while((c<1)||(c>4));

          clrscr();

          switch(c)

          { case 1 :

 do

{        cout<<"\n Queue currently has "<<q.count()<<" elements. ";

                             cout<<"\n Enter the new element";

                             cin>>num;

                              q.addq(num);

                             cout<<" Add More(Y/N) : ";

                             cin>>ch;

                 }

                 while((ch=='y')||(ch=='Y'));

                 break;

          case 2 :

int num;

                    do

{        cout<<"\n Queue currently has "<<q.count()<<"             elements. ";

                             if(num==q.delq()!=NULL)

                              cout<<num <<" element is deleted ";

                             cout<<"\n Current Queue is ";

                             q.display();

                             cout<<"\n Delete more(Y/N): ";

                             cin>>ch;

                    }

                    while((ch=='y')||(ch=='Y'));

                    break;

case 3 :       

cout<<"\n Queue Currently has "<<q.count()<<" elements as shown below. ";

                    q.display();

                    break;

           case 4 :

exit(1);

                    break;

          }

          cout<<"\n Press Any Key To Continue...";

          getch();

      }

}