thebbqcode

template <class T>
class node
{
public:
  node<T>* next;
  T value;
};

#include "node.h"
 
template <class T>
class Stack
{
public:
	Stack();
	~Stack();
	void push(T pNode);
	void printNodes();
	void pop();
	node<T>* getNode( int i );
 
private:
	node<T>* head;
	node<T>* current;	
};
 
template <class T>
Stack<T>::Stack()
{	
	head = NULL;
	current = head;		
}
 
template <class T>
Stack<T>::~Stack()
{
	current = head;
	node<T>* ptr;
	while ( current->next != NULL )
	{
		ptr = current->next;
		delete(current);
		current = ptr;
	}
	delete(ptr);
 
}
 
template <class T>
void Stack<T>::push(T pNode)
{
	node<T> *p = new node<T>( );
	p->next = NULL;
	p->value = pNode;
 
	if ( head == NULL )
	{
		head = p;
		current = head;
		return;
	}
	current->next = p;
	current = p;
 
}
 
template <class T>
void Stack<T>::printNodes()
{
	node<T>* iterator = head;
 
	while ( iterator != NULL )
	{
		cout << iterator->value << endl;
		iterator = iterator->next;
	}	
}
template<class T>
void Stack<T>::pop()
{
	node<T>* tmp = head;
	node<T>* previous;
	if ( head == NULL ) return; // if there is nothing in the Stack return
 
	while (true)
	{
 
		if ( tmp->next == NULL )
		{
			delete(tmp);
			previous->next = NULL;
			return;
		}
		previous = tmp;
		tmp = tmp->next;
	}
 
}
 
template <class T>
node<T>* Stack<T>::getNode( int i )
{
	node<T>* tmp = head;	// ptr to the node we want
	for ( int k = 0; k < i; k++ )
	{
		if ( tmp->next == NULL ) return NULL;
		tmp = tmp->next;	
	}
	return tmp;
}

#include <iostream>
#include "Stack.h"
 
using namespace std;
 
/* struct defining a basic person object */
struct person
{
	char* pzName;
	int pzAge;
};
 
 
int main()
{
	cout << "This is a Stack Example, so remember that stacks work on\n" <<
			"a last in first out basis, firstly we will do an int example\n" <<
			"followed by a character string Stack\n\n" << endl;
 
	/** create a int type stack */
	Stack<int> *p = new Stack<int>();
	p->push( 2 );
	p->push( 50 );
	p->push( 24 );
	p->push( 12 );
	p->printNodes();	// print our nodes added
	cout << "Now We Pop A Node" << endl;
	p->pop();
	p->printNodes();
	cout << "Notice the Difference ? " << endl;
	p->~Stack(); // deconstructor
 
	/** create a character pointer type example Stack */
	cout << "Now a char* stack example" << endl;
	Stack<char*> *str = new Stack<char*>();
	str->push("testing");
	str->push("stack");
	str->push("example");
	str->push("from");
	str->push("thebbqcode");
	str->printNodes();
	cout << "Now ->pop()" << endl;
	p->pop();
	str->printNodes();
	str->~Stack();	// deconstructor
	cout << "End of char* example\n\nPerhaps a double example?" << endl;
 
	/** Stack of floats */
	Stack<double> *flt = new Stack<double>();
	flt->push(2.38);
	flt->push(2.44);
	flt->push(19.23);
	flt->printNodes();
	cout << "Now we pop" << endl;
	flt->pop();
	flt->printNodes();
	cout << "End of float example " << endl;
	flt->~Stack();
 
	/**
		Now how about we create a few random structs or objects
		and use the template class to store them, we will create
		a person object, the person will have a name and age and we
		will use a struct to model this object.
		The struct is defined at the top of this file
	*/
 
	cout << "Now or person struct object examples\n\n" << endl;
 
	Stack<person> *per = new Stack<person>();
	person one, two, three;	// create some people
	// person one
	one.pzName = "Robert";
	one.pzAge = 25;
	// person two
	two.pzName = "Banga";
	two.pzAge = 17;
	//person three
	three.pzName = "cougz";
	three.pzAge = 28;
	// now push these persons onto the stack //
	//cout << "There are " << per->count << " nodes in the stack " << endl;
	per->push( one );
	per->push( two );
	per->push( three );
	//cout << "There are " << per->count << " nodes in the stack " << endl;
	// now in order to print these values, we would need to overload ofstream //
	// so in this case we will just assume that we have done so and leave it  //
	// at that, this is the reason it might be wise to include a function to  //
	// return a node so we can reach values witin it for objects			  //
	// as such a sample is implemented to show this.						  //
	per->pop();
	//cout << "There are " << per->count << " nodes in the stack " << endl;
	if ( per->getNode(1) != NULL )
	{
		cout << "Name : " << per->getNode(1)->value.pzName << endl;
		cout << "Age : " << per->getNode(1)->value.pzAge << endl;
	}
	else
		cout << "no nodes found" << endl;
	per->getNode(10);
	per->~Stack();
 
 
	getchar();
 
	return 0;
}