Си все про списки v2

#include <iostream>
using namespace std;
class Node
{
	int field;
	int field2;
	class Node *ptr;
	friend class List;
};

class List
{
	Node *head;
	int count = 0;
	Node* Prev(Node *); // Переход к предыдущему узлу (не интерфейсный метод)
public:
	List() { head = NULL; } // Инициализация списка
	int getCount() { return count; } // Получение количества узлов списка
	bool isEmpty() { return head == NULL; }  // Проверка, пуст ли список
	int getValue(Node* p) { return p->field; } // Получение значения узла списка
	int getValue2(Node* p) { return p->field2; } // Получение значения 2го узла списка
	void setValue(Node *p, int val) { p->field = val; } // Установка значения узла списка
	Node* getFirst() { return head; } // Получение корневого узла списка
	Node* getLast();			// Получение последнего узла списка
	void Clear();				// Очистка списка
	Node* Next(Node *);			// Переход к следующему узлу
	Node* Add(int, int, Node*); // Добавление узла списка
	Node* Delete(Node*);		// Удаление узла списка
	void Print();				// Вывод значений узлов списка
	void Swap(Node*, Node*);	// Взаимообмен двух узлов

	Node* Nomer_s_kontsa_del(); // удален середина по номеру
	Node* Zamena(); // замена
	Node* Zamena_ptr(); // замена по указателю
	Node* HeadToEnd(); // замена местами по указателю первый назад последний вперед
	Node* FILO(); // первый назад
	Node* LIFO(); // последний вперед

	Node* Dobav_n_last(int); // добавить в конец
	Node* Dobav_pre_last(); // добавить перед конец
	Node* Dobav_head(); // добавить перед конец
	Node* Dobav_head_next(); // добавить перед конец

	Node* head_del(); // udalit golovu
	Node* head_next_del(); // udalit 2 s golovu
	Node* Delete_end(); // удаляет конец
	Node* Delete_prev_end(); // удален предпоследний

	Node* By_value_del(); // udalit po znacheniu
};

Node* List::Add(int num, int num2, Node* node = NULL)
{
	Node *elem = new Node();
	elem->field = num;
	elem->field2 = num2;
	count++;
	if (node == NULL) // Добавление нового корня
	{
		if (head == NULL) {
			elem->ptr = NULL;
			head = elem;
		}
		else {
			elem->ptr = head;
			head = elem;
		}
		return elem;
	}
	elem->ptr = node->ptr; // Добавление узла после текущего
	node->ptr = elem;
	return elem;
}

Node* List::Delete(Node* node)
{
	if (node == NULL) { return NULL; } // В списке нет узлов
	count--;
	if (node == head)	// Удаление корневого узла
	{
		head = node->ptr;
		delete node;
		return head;
	}
	Node* prev = Prev(node); // Удаление промежуточного узла
	prev->ptr = node->ptr;
	delete node;
	return prev;
}
////////////////
Node* List::Delete_end()
{
	Node *temp = NULL;
	Node *head2 = head;
	if (head2 == NULL) { return NULL; } // В списке нет узлов
	count--;
	while (head2->ptr != NULL) {  // перемотка на последние указатели
		temp = head2;
		head2 = head2->ptr;
	}
	if (temp) {
		//<udalenie poslednego>
		temp->ptr = NULL;
		delete head2;
		//< /udalenie poslednego>
	}
	cout << temp->field  <<" - " << temp << " - " << temp->ptr << endl;
}
////////////////
////////////////
Node* List::Dobav_head()
{
	Node *temp = NULL;
	Node *head2 = head;
	//<opation>
	Node *elem2 = new Node();
	elem2->field = 88;
	elem2->ptr = head2;
	head = elem2;
	//</opation>
	if (head2 == NULL) { return NULL; } // В списке нет узлов
	count++;
}
////////////////
////////////////
Node* List::Dobav_head_next()
{
	Node *t1 = NULL;
	Node *t2 = head;
	t1 = head;
	t2 = t2->ptr;
	//<operation>
	Node *elem2 = new Node();
	elem2->field = 88;
	t1->ptr = elem2;
	elem2->ptr = t2;
	//<operation>
	if (t2 == NULL) { return NULL; } // В списке нет узлов
	count++;
}
////////////////
////////////////
Node* List::Dobav_n_last(int value = 88)
{
	Node *temp = NULL;
	Node *head2 = head;
	if (head2 == NULL) { return NULL; } // В списке нет узлов
	count++;
	while (head2->ptr != NULL) {
		temp = head2;
		head2 = head2->ptr;
	}
	// <operation>
	Node *elem2 = new Node();
	elem2->field = value;
	elem2->ptr = NULL;
	head2->ptr = elem2;
	// </operation>
	cout << head2->field << " test " << head2 << " test " << endl;
	cout << head2->ptr->field << " test " << head2->ptr << " test " << endl;
}
////////////////
/////////////////
Node* List::Dobav_pre_last()
{
	Node *temp = NULL;
	Node *t = head;
	Node *head2 = head;
	if (head2 == NULL) { return NULL; } // В списке нет узлов
	count--;
	while (head2->ptr != NULL) {
	head2 = head2->ptr;
	t = t->ptr;
		if (t->ptr->ptr == NULL) {
		temp = t->ptr;
		cout << t->field << " test2 " << t << " test2 " << endl;
		cout << temp->field << " test2 " << temp->ptr << " test2 " << endl;
		//<operation>
		Node *elem2 = new Node();
		elem2->field = 88;
		t->ptr = elem2;
		elem2->ptr = temp;
		//</operation>
		return NULL;
		}
	}
}
////////////////
////////////////
Node* List::Delete_prev_end()
{
	count++;
	Node *temp = NULL;
	Node *head2 = head;
	Node *t = head;
	Node *t2 = head;
	Node *t3 = head;
	if (head2 == NULL) { return NULL; } // В списке нет узлов
	if (head2->ptr == NULL) { return NULL; } // В списке нет узлов по условию
	if (head2->ptr->ptr == NULL) { return NULL; } // В списке нет узлов
	count--;
	int j = 0;
	cout << head2->field << " - " << head2 << " - " << endl;
	while (head2->ptr != NULL) {j++;
				head2 = head2->ptr;
				temp = head2;
				t = temp->ptr;
				t3 = t->ptr;
		cout << temp->field << " - " << temp << " - " << endl;
		cout << t->field << " - " << t << " - " << endl;
		cout << t3->field << " - " << t3 << " - " << endl;

		if (head2->ptr->ptr->ptr == NULL) {
			//// <operation>
			temp->ptr = t3; delete t;
			//// </operation>
			cout << temp->field << " Проверка " << temp << " - " << endl;
			cout << temp->ptr->field << " Проверка " << temp->ptr << " - " << endl;
			cout << "temp->ptr->ptr->field" << " Проверка " << temp->ptr->ptr << " - " << endl;
			cout << "t3->ptr->field" << " - " << t3->ptr << " - " << endl;
			return NULL;
		}
	}
}
///////////////////
////////////////
Node* List::Nomer_s_kontsa_del()
{
	count++;
	Node *temp = NULL;
	Node *head2 = head;
	Node *t = head;
	Node *t2 = head;
	Node *t3 = head;
	Node *t4 = head;
	int nomer_s_kontsa = 4;
	if (head2 == NULL) { return NULL;  } // В списке нет узлов
	count--;
	int i = 0;
	int vsego;
	while (t2->ptr != NULL) {
		t2 = t2->ptr;
		i++;
		vsego = i;
	}
	// proverka na sootvetstvie spisku
	if ((vsego+1) <= nomer_s_kontsa) { cout << " Nomer ne sootvetstvuet spisku|" << nomer_s_kontsa << "- этого номера нет " << endl;   return NULL; }

	cout << " vsego  " << (vsego+1) << " - " << endl;
	int j = 0;

	while (head2->ptr != NULL) {
		if (j == (vsego - nomer_s_kontsa)) {
				temp = head2;
				t = temp ->ptr;
				t3 = t->ptr;
				//// <perenos ukazatelya udalenie>
				temp->ptr = t3; delete t;
				//// </ perenos ukazatelya udalenie>
				cout << j << " Проверка " << temp << " - " << endl;
				head2 = head2->ptr;
		}
		else {
			head2 = head2->ptr;
		}
		j++;
	}
}
///////////////////
////////////////
Node* List::By_value_del()
{
	Node *temp = NULL;
	Node *head2 = head;
	Node *t = head;
	Node *t2 = head;
	Node *t3 = head;
	Node *t4 = head;
	int value_del = 31;
	if (head2 == NULL) { return NULL; } // В списке нет узлов
	count--;
	int j = 0;
	while (head2->ptr != NULL) {
		temp = head2;
		head2 = head2->ptr;
		if (head2->field == value_del) {
			t = temp->ptr;
			t3 = t->ptr;
			//// <operation>
			temp->ptr = t3; delete t;
			//// </operation>
			cout << j << " Проверка " << temp << " - " << endl;
			break;
		}
		else {
		}
		j++;
	}
}
///////////////////
////////////////
Node* List::head_next_del()
{
	Node *t1 = NULL;
	Node *head2 = head;
	Node *t2 = head;
	Node *t3 = head;
	t1 = head;
	t2 = t1->ptr;
	t3 = t2->ptr;
	if (head2 == NULL) { return NULL; } // В списке нет узлов
	// <ukazateli dlya operatsii>
	cout << t1->field << " - " << t1 << " - " << endl;
	cout << t2->field << " - " << t2 << " - " << endl;
	cout << t3->field << " - " << t3 << " - " << endl;
	// </ukazateli dlya operatsii>
	// <operation>
	t1->ptr = t3;
	t2->ptr = NULL;
	delete t2;
	// </operation>
	// <proverka>
	cout << head2->field << " - " << head2 << " - " << endl;
	cout << head2->ptr->field << " - " << head2->ptr << " - " << endl;
	cout << head2->ptr->ptr->field << " - " << head2->ptr->ptr << " - " << endl;
	// </proverka>
}
////////////////
////////////////
Node* List::head_del()
{
	Node *temp = NULL;
	Node *head2 = head;
	Node *t = head;
	if (head2 == NULL) { return NULL; } // В списке нет узлов
	//<operation>
	head = head2->ptr;
	t = NULL;
	delete t;
	//</operation>
	int i = 0;
	while (head2->ptr != NULL) {
		temp = head2;
		head2 = head2->ptr;
		cout << i << " - " << t << " - " << endl;
		cout << i << " - " << temp << " - " << endl;
		cout << i << " - " << head2->ptr << " - " << endl;
		i++;
	}
}
////////////////
////////////////
Node* List::Zamena_ptr()
{
	Node *temp = NULL;
	Node *head2 = head;
	Node *t = head;
	Node *t2 = head;
	Node *t3 = head;
	Node *t4 = head;
	if (head2 == NULL) { return NULL; } // В списке нет узлов
	int i = 0;
	int n_zameny=5;
		while (head2->ptr != NULL) {
		t2 = head2;
		head2 = head2->ptr;
		if (i == (n_zameny-2)) {
			temp = head2;
			cout << " Замена " << n_zameny << endl;
			head2 = head2->ptr;
			t3 = temp->ptr;
			// <vivod nuzhnih peremennih>
			cout << t->field << " - " << t << " - " << endl;
			cout << t2->field << " - " << t2 << " - " << endl;
			cout << temp->field << " - " << temp << " - " << endl;
			cout << t3->field << " - " << t3 << " - " << endl;
			// </vivod nuzhnih peremennih>
			// </ podstanovka>
			 t4 = t4->ptr;
			 t2->ptr = t; t->ptr = t3;
			 head = temp;
			 temp->ptr = t4;
			 // < podstanovka>
			 // < proverka>
			cout << head->field << " 1 " << head << " - " << endl;
			cout << t2->field << " n " << t2 << " - " << endl;
			cout << t2->ptr->field << " n+1 " << t2->ptr << " - " << endl;
			cout << t3->field << " n+2 " << t3 << " - " << endl;
			// < proverka>
		}
		i++;
	}
}
///////////////////
////////////////
Node* List::HeadToEnd()
{
	Node *temp = NULL;
	Node *head2 = head;
	Node *t = head;
	Node *t2 = head;
	Node *t3 = head;
	Node *t4 = head;
	if (head2 == NULL) { return NULL; } // В списке нет узлов
	int i = 0;
	int n_zameny = 10;
	while (head2->ptr != NULL) {
		head2 = head2->ptr;
		t2 = head2;
		if (t2->ptr->ptr->ptr == NULL) {
			t2 = head2;
			temp = t2->ptr;
			cout << " Замена " << n_zameny << endl;
			//head2 = head2->ptr;
			t3 = temp->ptr;
			// <vivod nuzhnih peremennih>
			cout << t->field << " - " << t << " - " << endl;
			cout << t2->field << " - " << t2 << " - " << endl;
			cout << temp->field << " - " << temp << " - " << endl;
			cout << t3->field << " - " << t3 << " - " << endl;
			// </vivod nuzhnih peremennih>
			// </ podstanovka>
			t4 = t4->ptr;
			head = t3;
			t3->ptr = t4;
			temp->ptr = t; t->ptr = NULL;
			// < podstanovka>
			return NULL;
		}
		i++;
	}
}
///////////////////
////////////////
Node* List::LIFO()
{
	Node *temp = NULL;
	Node *head2 = head;
	Node *t = head;
	Node *tt = head;
	Node *t2 = head;
	Node *t3 = head;
	Node *t4 = head;
	if (head2 == NULL) { return NULL; } // В списке нет узлов
	int i = 0;
	int n_zameny = 10;
	while (head2->ptr != NULL) {
		head2 = head2->ptr;
		t2 = head2;
		if (t2->ptr->ptr->ptr == NULL) {
			t2 = head2;
			temp = t2->ptr;
			cout << " Замена " << n_zameny << endl;
			//head2 = head2->ptr;
			t3 = temp->ptr;
			// <vivod nuzhnih peremennih>
			cout << t->field << " -- " << t << " - " << endl;
			cout << t2->field << " -- " << t2 << " - " << endl;
			cout << temp->field << " -- " << temp << " - " << endl;
			cout << t3->field << " -- " << t3->ptr << " - " << endl;
			// </vivod nuzhnih peremennih>
			// </ podstanovka>
			head = t3;
			t3->ptr = t;
			temp->ptr = NULL;
			// < podstanovka>
			return NULL;
		}
		i++;
	}

}
///////////////////
////////////////
Node* List::FILO()
{
	Node *temp = NULL;
	Node *head2 = head;
	Node *t = head;
	Node *tt = head;
	Node *t2 = head;
	Node *t3 = head;
	Node *t4 = head;
	if (head2 == NULL) { return NULL; } // В списке нет узлов
	int i = 0;
	int n_zameny = 10;
	while (head2->ptr != NULL) {
		head2 = head2->ptr;
		t2 = head2;
		if (t2->ptr->ptr->ptr == NULL) {
			t2 = head2;
			temp = t2->ptr;
			cout << " Замена " << n_zameny << endl;
			//head2 = head2->ptr;
			t3 = temp->ptr;
			// <vivod nuzhnih peremennih>
			cout << t->field << " -- " << t << " - " << endl;
			cout << t2->field << " -- " << t2 << " - " << endl;
			cout << temp->field << " -- " << temp << " - " << endl;
			cout << t3->field << " -- " << t3->ptr << " - " << endl;
			// </vivod nuzhnih peremennih>
			// </ podstanovka>
			t4 = t4->ptr;
			head = t4;
			t3->ptr = t;
			t->ptr = NULL;
			// < podstanovka>
			return NULL;
		}
		i++;
	}

}
///////////////////
////////////////
Node* List::Zamena()
{
	Node *temp = NULL;
	Node *head2 = head;
	Node *t = head;
	if (head2 == NULL) { return NULL; } // В списке нет узлов
	int i = 0;
	int n_zameny;
	cout <<  " Введи номер замены " << endl;
	cin >> n_zameny;

	while (head2->ptr != NULL) {
		if (i == (n_zameny-1)) {
			temp = head2;
			cout << " Замена " << n_zameny << endl;
		}
		head2 = head2->ptr;
		cout << i << " - " << t << " - " << endl;
		cout << i << " - " << temp << " - " << endl;
		cout << i << " - " << head2->ptr << " - " << endl;
		i++;
	}
	if (temp) {
		int zamen1;
		zamen1 = temp->field;
		temp->field = t->field; // вставляем значение первого в выбранный
		t->field = zamen1; // вставляем в первый значение выбранного
	}
}
///////////////////
void List::Print()
{
	if (isEmpty()) { cout << "Список пуст" << endl; return; }
	Node *p = head;
	do {
		cout << "(" <<getValue(p)<< " "
			//<< getValue2(p)
			<< ")";
		p = Next(p);
	} while (p != NULL);
	cout << endl;
}

void List::Clear()
{
	class Node *p = head;
	if (p == NULL) return;
	do {
		Node *d = p;
		p = Next(p);
		delete d;
	} while (p != NULL);
	count = 0;
	head = NULL;
}

Node* List::getLast()
{
	Node* p = head;
	while (Next(p) != NULL)
		p = Next(p);
	return p;
}

Node* List::Next(Node* node)
{
	if (isEmpty()) return NULL;
	return node->ptr;
}

Node* List::Prev(Node* node)
{
	if (isEmpty()) return NULL;
	if (node == head) return NULL;
	Node *p = head;
	while (p->ptr != node)
		p = p->ptr;
	return p;
}

void List::Swap(Node* node1, Node* node2)
{
	if (node1 == NULL || node2 == NULL) return;
	if (node1 == node2) return;
	if (node2->ptr == node1)
	{
		Node *p = node1;
		node1 = node2;
		node2 = p;
	}
	Node *prev1 = Prev(node1);
	Node *prev2 = Prev(node2);
	Node *next1 = Next(node1);
	Node *next2 = Next(node2);
	if (next1 == node2)
	{
		if (prev1 != NULL)
			prev1->ptr = node2;
		else
			head = node2;
		node2->ptr = node1;
		node1->ptr = next2;
		return;
	}
	if (prev1 != NULL)
		prev1->ptr = node2;
	else
		head = node2;
	if (prev2 != NULL)
		prev2->ptr = node1;
	else
		head = node1;
	node2->ptr = next1;
	node1->ptr = next2;
}



int main()
{
	system("chcp 1251");
	system("cls");
	List list;
	list.Print();
	Node *s = list.getLast();
	for (int i = 0; i < 5; i++) {
		int z;
		int z2=0;
		cout << ">> field1-  ";
		cin >> z;
		//cout << ">> field2-  ";
		//cin >> z2;
		s = list.Add(z, z2, s);
	}
	//list.Delete_end();
	//list.Nomer_s_kontsa_del();
	//list.By_value_del();
	//list.Delete_prev_end();
	//list.head_del();
	//list.Zamena();
	//list.Zamena_ptr();
	//list.head_next_del();
	//list.Dobav_n_last();
	//list.Dobav_pre_last();
	//list.Dobav_head();
	//list.Dobav_head_next();
	//list.HeadToEnd();
	//list.FILO();
	list.LIFO();
	cout << "***********************" << endl;
	list.Print();
	cout << "Последний элемент: " << list.getValue(list.getLast()) << endl;
	// Удаляем элементы, равные 0
	Node *p = list.getFirst();
	do {
		if (list.getValue(p) == 0)
			p = list.Delete(p);
		else
			p = list.Next(p);
	} while (p != NULL);
	list.Print();
	cout << "В списке " << list.getCount() << " элементов" << endl;
	//list.Swap(list.getFirst(), list.getLast());
	list.Print();
	list.Clear();
	list.Print();
	cout << "В списке " << list.getCount() << " элементов" << endl;
	cin.get(); cin.get();

	return 0;
}