Реализовать двунаправленный список и отсортировать его!

/*Athor Igor Dombrovsky
Realiztion SORT LIST <====>
*/
#include <iostream> // COUT
#include <time.h> // RAND
#include <stdlib.h> // RAND
using namespace std;  // STD
#define TEXT_COLOR_CMD_WINDOWS_GREEN system("color 0A"); // COLOR CMD
#define STOP_CMD_WINDOWS system("pause"); // SYSTEM PAUSE

template<class T> // TEMPLATE CLASS LIST
class List
{
public:
	List(); 
	~List();
	void addElement(T element); 
	void listSort();
	int getSizeList(); 
	void showListHead(); 
	void showListTail();
private:
	List * head;
	List * tail;
	List * next;
	List * previuos;
	T data;
	int size; 
};

template<class T>
List<T>::List() : size(0) // CONSTRUCTOR
{
	head = tail = next = previuos = NULL; 
}

template<class T>
List<T>::~List() // DESTRUCTOR
{
	size = 0;
}

template<class T>
void List<T>::addElement(T element) // ADD ELEMENTS LIST
{
	List * temp = new List; 

	if (head == NULL)
	{
		head = tail = temp; 
		head->previuos = NULL; 
		tail->next = NULL; 
		head->data = element; 
		this->size++; 
	}
	else
	{
		tail->next = temp; 
		temp->previuos = tail; 
		tail = temp;
		tail->data = element; 
		this->size++; 
	}
}

template<class T>
void List<T>::listSort() // BOOBLE SORT LIST
{
	List * temp = new List; 
	List * indexHead = head; 
	List * indexTail = tail; 
	for (size_t i = 1; i <= this->size; i++)
	{
		for (size_t j = this->size - 1; j >= i; j--)
		{
			if (indexHead->data > indexTail->data)
			{ 
				temp->data = indexHead->data;
				indexHead->data = indexTail->data;
				indexTail->data = temp->data;
			}
			indexTail = indexTail->previuos;  
		} 
		indexHead = indexHead->next; 
		indexTail = tail;
	}
	delete temp; 
}

template<class T>
int List<T>::getSizeList() // GET SIZE LIST
{
	return this->size;
}

template<class T>
void List<T>::showListHead() // DISPLAY LIST MIN MAX
{
	List * temp = head; 
	while (temp != NULL)
	{
		cout << temp->data << "\t"; 
		temp = temp->next; 
	}
	cout << endl; 
}

template<class T>
void List<T>::showListTail() // DISPLAY LIST MAX MIN
{
	List * temp = tail;
	while (temp != NULL)
	{
		cout << temp->data << "\t";
		temp = temp->previuos;
	}
	cout << endl;
}

int main() {
	TEXT_COLOR_CMD_WINDOWS_GREEN // GREEN TEXT CMD BACKGROUND BLACK
		srand(time(0)); // RAND TIME ZERO
	List<int> l; // LIST
//*********************************************
// ADD LIST RANDOM ELEMENTS
//*********************************************
	for (size_t i = 1; i <= 10; i++)
		l.addElement(rand() % (i * 10));
//*********************************************
// DISPLAY LIST MIN MAX
//*********************************************
	l.showListHead();
//*********************************************
// DISPLAY LIST MAX MIN
//*********************************************
	l.showListTail();
//*********************************************
// GET SIZE LIST
//*********************************************
	cout << "SIZE = " << l.getSizeList() << endl; 
//*********************************************
// SORT LIST
//*********************************************
	l.listSort(); 
//*********************************************
// DISPLAY LIST MIN MAX
//*********************************************
	l.showListHead();
//*********************************************
// DISPLAY LIST MAX MIN
//*********************************************
	l.showListTail();
//*********************************************
	STOP_CMD_WINDOWS // SYSTEM PAUSE CMD WINDOWS
	return 0; 
}