Dequeue (Double-ended queue) operations

/*Program to impelement Dequeue operations
compiler- Turbo c++     author- Mangilal Sharma
--------------------------------------------------------*/
#include<iostream.h>
#include<conio.h>
#include<process.h>
#define max 5

class dqueue
{
 private:
 int queue_arr[max],rear,front,choice;
 public:
 void insertL();
 void insertR();
 void delL();
 void delR();
 void display();
 void menu(int);
 dqueue();
};

void dqueue::insertL()
{
 int added_item;
 if(front==0)
 {
  cout<<"Queue is Overflow\n";
  return;
 }
 else
 {
  cout<<"\n               Insert the element for adding in DeQueue: ";
  cin>>added_item;
 }
 front=front-1;
 queue_arr[front]=added_item;
}

void dqueue::insertR()
{
 int added_item;
 if(rear==(max-1))
 {
  cout<<"Queue is Overflow\n";
  return;
 }
 else
 {
  cout<<"\n               Insert the element for adding in DeQueue: ";
  cin>>added_item;
 }
   if(front==-1)
  front=0;
 rear=rear+1;
 queue_arr[rear]=added_item;
}

void dqueue::delR()
{
 if(front==rear+1)
 {
  cout<<"DeQueue is Underflow\n";
  return;
 }
 else
  cout<<"Element delete from DeQueue is "<<queue_arr[rear];
 rear=rear-1;
}

void dqueue::delL()
{
 if(front==rear+1)
 {
  cout<<"DeQueue is Underflow\n";
  return;
 }
 else
  cout<<"Element delete from DeQueue is "<<queue_arr[front];
 front=front+1;
}

void dqueue::display()
{
 int i;
 if(front<=rear)
 {
  cout<<"DeQueue is:\n";
  for(i=front;i<=rear;i++)
  cout<<queue_arr[i];
  cout<<"\n";
 }
 else
 {
 cout<<"Dequeue is empty";
 }
}

void dqueue::menu(int n)
{
 while(1)
 {
  cout<<"\n\t\t\t        Menu";
  cout<<"\n\n\t\t1. To Insert an Element\n";
  if(n==2)
  cout<<"\t\t2. To Insert an Element at left\n";
  if(n==1)
  cout<<"\t\t2. To Delete an Element from right\n";
  cout<<"\t\t3. To Delete an Element\n";
  cout<<"\t\t4. To Display the Elements of DeQueue\n";
  cout<<"\t\t5. To Exit from Programme\n";
  cout<<"\n\t\t      Enter Your Choice= ";
  cin>>choice;
  switch(choice)
  {
   case 1:insertR();break;
   case 2:if(n==1)delR();
 if(n==2)insertL();break;
   case 3:delL();break;
   case 4:display();break;
   case 5:exit(1);
   default: cout<<"\n\t\tWrong Choice, Enter Again\n";
  }
 }
}

dqueue::dqueue()
{
 rear=-1,front=-1;
 cout<<"\n\t\t\t    DQUEUE\n";
 cout<<"\t\t1. input restriced dequeue\n";
 cout<<"\t\t2. output restriced dequeue\n";
 cout<<"\t\t3. To main menu\n";
 cout<<"\t\t4. To Exit from Programme\n";
 cout<<"\n\t\t Enter Your Choice= ";
 cin>>choice;
 switch(choice)
 {
  case 1:
  menu(1);break;
  case 2:
  menu(2);break;
  case 3:
return;
  case 4:
exit(1);
  default:
 cout<<"\n\t\tWrong Choice, Enter Again\n";
 }
}
/*=========================6Nov.,2010=============================*/