#include <assert.h>
#include <iostream.h>
//////////////////////////mydefs1c.h/////////////
class Istack {
	int sz;
	int top;
	int* stack;
public:
	Istack(void)	// One creator 
	    { sz = 97; stack = new int[sz]; top = sz; 
			cout << "using default creator 97\n";}
	Istack(int Nitems )	// Another creator
		{ sz = Nitems; stack = new int[sz]; top = sz; 
		    cout << "using pre-set creator " << Nitems << "\n"; }
	~Istack() 		// The destructor
	    { delete[] stack; } 
					// delete[] removes array space
	void push(int x) 
	    { assert( !isfull() ); stack[--top] = x; }
	int pop() 
	    { assert( !isempty() ); return( stack[top++] ); }
	bool isempty() 
	    { return( top == sz ); }
	bool isfull() 
	    { return( top == 0); }
};

//////////////////////stackmain1c.cc///////////////

void main()
{
	Istack s1(500);
	Istack s2; 		// default constructor?
	Istack s3(); 	// a function which returns Istack
	Istack s6(137); 
	Istack s4[5]; 	// default constructor called 5 times here
	Istack s9(23);
	Istack* s5;		// no space, just a pointer

//	Istack s8[2](137); 	// array of two stacks size 137, NO
//	Istack s7()[2];		// s7() is a function returning an array!
//	Istack s10(23)[2];	// two 23-element stacks?  No way, can only use default

	int i;

	for( i = 0; i < 20; i++ ) {
		s1.push(i);			// s1 is a 500 element stack
	}

	for( i = 0; i < 20; i++ ) {
		cout << s1.pop() << ' ';
	}
	cout << endl;
	
//	s3.push(10);			// s3 is a function, not a stack
//	cout <<  s3.pop() << ' ';

	s4[3].push(11);		// 3rd stack in the array
	cout << s4[3].pop() << ' ';
	
	s5 = new Istack;		// get stack space, which constructor?	
	s5->push(12);			// pointing to a stack
	cout << s5->pop() << endl;
	delete s5;				// explicit removal
}
/*

using pre-set creator 500
using default creator 97
using pre-set creator 137
using default creator 97
using default creator 97
using default creator 97
using default creator 97
using default creator 97
using pre-set creator 23
19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 
11 using default creator 97
12
*/