//Syed Rais Ahmad.
//CIS:610 Dynamic Data Struc.
//Assignment # 5 Question # 1a
//Empty, push,pop,popandtest using array

#include<iostream.h>
#define MAX 32

class Stack
{
private:
	int  * data; //data value in stack
	unsigned sp;      // Stack Pointer
	unsigned spMax;   //Max Stack Pointer Value;
public:
	Stack() ;
	void push(int );
	int pop();

	int popNTest() ;
	int StackTop();
	bool Empty(void);
	
};

//Constructor
Stack::Stack()
{ 
	data=new int(MAX);	//init data 
	sp=0;				//Stack initialized
	spMax=MAX-1;			
	data[0]=NULL;		
}
//push
void Stack::push(int item)
{
	data[++sp]=item;
}

int Stack::pop()
{
	return data[sp--];
}


//Return the Top most element of stack and decrement the SP
int Stack::popNTest()
{ 
	if (sp>0) return data[sp--]; 
	else return -1;
}

//Is stack empty?
bool Stack::Empty()
{
	return (sp)? false : true;			
	
}


main()
{
Stack s;
s.push(9);
s.push(11);

cout << "\nPushed 9,11. Pop = " <<  s.pop();
cout << "\nEmpty() returns:" << s.Empty();
cout << "\npopNTest() returns: " << s.popNTest() ;
cout << "\nEmpty() returns:" << s.Empty() << '\n';

return 0;

}