/// <summary>
/// Returns the list reversed in place
/// </summary>
public void Reverse()
{
// does not work - when start is called in AddFirst - its next value is reseted to null
// and so it loses further reference
//var start = this.Head;
//var reversedList = new LinkedList<T>();
//while (start != null)
//{
// reversedList.AddFirst(start);
// start = start.Next;
//}
//return reversedList;
if (this.Head == null)
{
Console.WriteLine("List is empty!");
}
else
{
var current = this.Head;
NodeLL <T> temp = null;
while (current != null)
{
temp = current.Next;
current.Next = current.Prev;
current.Prev = current;
// if this is outside of loop => current.prev is null
this.Head = current.Prev;
current = temp;
}
}
}
/// <summary>
/// overloaded method taking a whole node
/// </summary>
/// <param name="node"></param>
public void AddFirst(NodeLL <T> node)
{
node.Next = this.Head;
node.Prev = null;
if (this.Head != null)
{
this.Head.Prev = node;
}
this.Head = node;
Size++;
}
public void AddFirst(T val)
{
var node = new NodeLL <T>(val);
node.Next = this.Head;
node.Prev = null;
if (this.Head != null)
{
this.Head.Prev = node;
}
this.Head = node;
Size++;
}
// HackerRank Print();
public static void Print(NodeLL <T> head)
{
if (head == null)
{
return;
}
else
{
var temp = head;
while (temp != null)
{
Console.WriteLine(temp.Value);
temp = temp.Next;
}
}
}
public void AddBefore(NodeLL <T> node, T Val)
{
if (node == null)
{
Console.WriteLine("NodeLL cannot be null!");
}
else
{
var newNodeLL = new NodeLL <T>(Val);
newNodeLL.Next = node;
newNodeLL.Prev = node.Prev;
node.Prev = newNodeLL;
if (newNodeLL.Prev != null)
{
newNodeLL.Prev.Next = newNodeLL;
}
}
}
/// <summary>
/// Returns a new instance with the list reversed;
/// </summary>
public LinkedList <T> ReverseList()
{
var current = new NodeLL <T>(this.Head);
NodeLL <T> temp = null;
var reversedList = new LinkedList <T>();
while (true)
{
temp = new NodeLL <T>(current);
reversedList.AddFirst(current);
if (temp.Next == null)
{
break;
}
//
current = new NodeLL <T>(temp.Next);
}
return(reversedList);
}
public void AddAfter(NodeLL <T> node, T val)
{
if (node == null)
{
Console.WriteLine("NodeLL cannot be null!");
}
else
{
var newNodeLL = new NodeLL <T>(val);
newNodeLL.Next = node.Next;
node.Next = newNodeLL;
newNodeLL.Prev = node;
if (newNodeLL.Next != null)
{
newNodeLL.Next.Prev = newNodeLL;
}
}
}
public void DeleteByValue(T value)
{
var temp = this.Head;
var isFound = false;
var nodeToRemove = new NodeLL <T>(default(T));
while (temp != null)
{
if (temp.Value.Equals(value))
{
nodeToRemove = temp;
isFound = true;
break;
}
temp = temp.Next;
}
if (isFound)
{
if (nodeToRemove.Prev == null)
{
this.Head = nodeToRemove.Next;
this.Head.Prev = null;
}
else if (nodeToRemove.Next == null)
{
nodeToRemove.Prev.Next = null;
}
else
{
nodeToRemove.Prev.Next = nodeToRemove.Next;
nodeToRemove.Next.Prev = nodeToRemove.Prev;
}
}
else
{
Console.WriteLine("No node with such value!");
}
}
// Insert at the end - HackerRank
public static NodeLL <T> Insert(NodeLL <T> head, T x)
{
if (head == null)
{
Console.WriteLine("List is empty! Add something first!");
return(default(NodeLL <T>));
}
var newNodeLL = new NodeLL <T>(x);
var current = head;
while (current.Next != null)
{
current = current.Next;
}
current.Next = newNodeLL;
newNodeLL.Prev = current;
newNodeLL.Next = null;
return(head);
}
public void AddLast(T val)
{
// AddLast in Constant time with Last variable
// Is it possible?
var node = new NodeLL <T>(val);
if (this.Head == null)
{
node.Prev = null;
Head = node;
}
else
{
var temp = this.Head;
while (temp.Next != null)
{
temp = temp.Next;
}
temp.Next = node;
node.Prev = temp;
node.Next = null;
}
Size++;
}
// copy constructor
public NodeLL(NodeLL <T> node)
{
this.Next = node.Next;
this.Prev = node.Prev;
this.Value = node.Value;
}
public void RemoveByNodeLL(NodeLL <T> node)
{
throw new NotImplementedException();
}