Data Structures using C++

  # include < iostream.h > 
  # include < conio.h > 
  # define SIZE 20 
  class queue 
  { 
     int a[SIZE]; 
     int front; 
     int rear; 
    public: 
       queue(); 
       ~queue(); 
       void insert(int i); 
       int remove(); 
       int isempty(); 
       int isfull(); 
  }; 
  queue::queue() 
  { 
    front=0; 
    rear=0; 
  } 
  queue::~queue() 
  { 
    delete []a; 
  } 
  void queue::insert(int i) 
  { 
    if(isfull()) 
    { 
       cout<<"*Queue is FULL !!!No insertion allowed further.*"; 
       return; 
    } 
    a[rear] = i; 
    rear++; 
  } 
  int queue::remove() 
  { 
    if(isempty()) 
    { 
       cout<<"*Queue Empty !!!Value returned will be garbage.*"; 
       return (-9999); 
    } 
    return(a[front++]); 
  } 
  int queue::isempty() 
  { 
    if(front == rear) 
       return 1; 
    else 
       return 0; 
  } 
  int queue::isfull() 
  { 
    if(rear == SIZE) 
       return 1; 
    else 
       return 0; 
  } 
  void main() 
  { 
    clrscr(); 
    queue q; 
    q.insert(1); 
    q.insert(2); 
    cout<<""<< q.remove(); 
    cout<<""<< q.remove(); 
    cout<<"" << q.remove(); 
    getch(); 
  }