//-----stack.cpp---------
//---------------------------------------------------------------------------
#include <vcl.h>
#pragma hdrstop

//---------------------------------------------------------------------------
#pragma package(smart_init)

#include "Stack.h"
#include <iostream.h>


StringStack::StringStack()
{
    head = 0;
}

StringStack::~StringStack()
{
    StringNode* temp;
    while(head!=0)
    {
        temp=head;
        head = head->next;
        delete temp;
    }
}


void StringStack::push(string push_string)
{
    StringNode* newNode = new StringNode(0, push_string);
    if(head==0)
        head = newNode;
    else
    {
        StringNode* ptr=head;
        while(ptr->next!=0)
            ptr=ptr->next;
        ptr->next = newNode;
    }
}

string StringStack::pop()
{
    if(head==0)
    {
    		cerr << "Stack Underflow.";
      	return "0";
    }

    StringNode* tempPtr = head->next;

    temp_string = head->data;
    delete head;
    head = tempPtr;

    return temp_string;
}





//-----Stack.h ----------
#include <vcl.h>
//---------------------------------------------------------------------------
#ifndef StackH
#define StackH
//---------------------------------------------------------------------------


#include "StringNode.h"

class StringStack
{
    public:
        StringStack();
        ~StringStack();
        void push(string);
        string pop();

    private:
        StringNode* head;
}; 
#endif