Lecture20code-stack.txt

/*
 *  File: mystack.h
 *  ----------------
 *
 *  Created by Julie Zelenski on 2/27/08.
 *
 */
#ifndef _mystack_h
#define _mystack_h

#include "genlib.h"
#include "vector.h"

template <typename ElemType>
class MyStack
{
 public:
	MyStack();
	~MyStack();
	
	bool isEmpty();
	void push(ElemType e);
	ElemType pop();
	
  private:
	struct cellT {
		ElemType val;
		cellT *next;
	};
	
	cellT * head;

};

#include "mystack.cpp"


#endif

/*
 *  File: mystack.cpp
 *  ------------------
 *
 *  Created by Julie Zelenski on 2/27/08.
 *
 */

#include "mystack.h"

template <typename ElemType>
MyStack<ElemType>::MyStack()
{	
	head = NULL;
}

template <typename ElemType>
MyStack<ElemType>::~MyStack()
{
	// delete the entire list
}


template <typename ElemType>
bool MyStack<ElemType>::isEmpty()
{
	return (head == NULL);
}


template <typename ElemType>
void MyStack<ElemType>::push(ElemType s)
{
	cellT *newCell = new cellT;
	newCell->val = s;
	newCell->next = head;
	head = newCell;
}

template <typename ElemType>
ElemType MyStack<ElemType>::pop()
{
	if (isEmpty()) Error("pop empty stack");
	ElemType top = head->val;
	cellT *old = head;
	head = head->next;
	delete old;
	return top;
}