public bool Contains(int data)
{
DoublyNode <int> current = head;
while (current != null)
{
if (current.Data.Equals(data))
{
return(true);
}
current = current.Next;
}
return(false);
}
public void PrintList()
{
if (head == null)
{
Console.WriteLine("Пустой список");
return;
}
DoublyNode <int> p = head;
while (p != null)
{
Console.WriteLine(p);
p = p.Next;
}
}
// добавление элемента
public void Add(int data)
{
DoublyNode <int> node = new DoublyNode <int>(data);
if (head == null)
{
head = node;
}
else
{
tail.Next = node;
node.Previous = tail;
}
tail = node;
count++;
}
public void AddFirst(int data)
{
DoublyNode <int> node = new DoublyNode <int>(data);
DoublyNode <int> temp = head;
node.Next = temp;
head = node;
if (count == 0)
{
tail = head;
}
else
{
temp.Previous = node;
}
count++;
}
// удаление
public bool Remove(int data)
{
DoublyNode <int> current = head;
// поиск удаляемого узла
while (current != null)
{
if (current.Data.Equals(data))
{
break;
}
current = current.Next;
}
if (current != null)
{
// если узел не последний
if (current.Next != null)
{
current.Next.Previous = current.Previous;
}
else
{
// если последний, переустанавливаем tail
tail = current.Previous;
}
// если узел не первый
if (current.Previous != null)
{
current.Previous.Next = current.Next;
}
else
{
// если первый, переустанавливаем head
head = current.Next;
}
count--;
return(true);
}
return(false);
}
public void ShowSum()
{
int number = 0;
if (count % 2 != 0)
{
Console.WriteLine("Нечетное кол-во элементов!");
}
else
{
DoublyNode <int> p = head;
DoublyNode <int> n = tail;
do
{
sum += 2 * (p.Data * n.Data);
p = p.Next;
n = n.Previous;
number++;
} while (number != count / 2);
Console.WriteLine(sum);
}
}
public void Clear()
{
head = null;
tail = null;
count = 0;
}