C++ program to implement Queue using Formula Based Representation

#include <iostream.h>
#include <conio.h>
class queue
{
private :
 
int *arr ;
int front, rear ;
int MAX ;
public :
queue( int maxsize = 10 ) ;
void addq ( int item ) ;
int delq( ) ;
} ;
queue :: queue( int maxsize )
{
MAX = maxsize ;
arr = new int [ MAX ];
front = -1 ;
rear = -1 ;
}
void queue :: addq ( int item )
{
if ( rear == MAX - 1 )
{
cout << "\nQueue is full" ;
return ;
}
rear++ ;
arr[rear] = item ;
if ( front == -1 )
front = 0 ;
}
int queue :: delq( )
{
int data ;
 
if ( front == -1 )
{
cout << "\nQueue is Empty" ;
return NULL ;
}
 
data = arr[front] ;
arr[front] = 0 ;
if ( front == rear )
front = rear = -1 ;
else
front++ ;
 
return  data ;
}
void main( )
{
queue a (10 ) ;
clrscr();
a.addq ( 23 ) ;
a.addq ( 9 ) ;
a.addq ( 11 ) ;
a.addq ( -10 ) ;
a.addq ( 25 ) ;
a.addq ( 16 ) ;
a.addq ( 17 ) ;
a.addq ( 22 ) ;
a.addq ( 19 ) ;
a.addq ( 30 ) ;
a.addq ( 32 ) ;
int i = a.delq( ) ;
cout << "\nItem deleted: " << i ;
i = a.delq( ) ;
cout << "\nItem deleted: " << i ;
i = a.delq( ) ;
cout << "\nItem deleted: " << i ;
}