Write a program showing implementation of stack class having the functionality of push, pop operations.

#include<iostream.h>
#define MAX 10
class stack
{
private:
int arr[ MAX ], top;
public:
stack( )
{
top = -1;
}
void push( int item )
{
if( top == MAX - 1 )
{
cout << endl << "Stack is full";
return;
}
top++;
arr[ top ] = item;
}
int pop( )
{
if( top == -1 )
{
cout << endl << "Stack is empty";
return NULL;
}
int data = arr[ top ];
top--;
return data;
}
};
void main( )
{
stack s;
s.push( 11 );
s.push( 12 );
s.push( 13 );
s.push( 14 );
s.push( 15 );
s.push( 16 );
s.push( 17 );
s.push( 18 );
s.push( 19 );
s.push( 20 );
s.push( 21 );
int i = s.pop( );
cout << endl << "Item popped=" << i;
i = s.pop( );
cout << endl << "Item popped=" << i;
i = s.pop( );
cout << endl << "Item popped=" << i;
i = s.pop( );
cout << endl << "Item popped=" << i;
}