/// <summary>
/// remove the tail of the list
/// </summary>
/// <returns></returns>
public bool RemoveLast()
{
if (_head == null)
{
return(false);
}
if (_head == _tail)
{
_head = null;
_tail = null;
return(true);
}
var prev = _head;
while (prev.Next != _tail)
{
prev = prev.Next;
}
prev.Next = null;
_tail = prev;
return(true);
}
/// <summary>
/// Add a node after a specific node
/// both cannot be null
/// </summary>
/// <param name="node"></param>
/// <param name="newNode"></param>
public void AddAfter(LListNode <T> node, LListNode <T> newNode)
{
if (node == _tail)
{
AddLast(newNode);
}
else
{
newNode.Next = node.Next;
node.Next = newNode;
}
}
/// <summary>
/// Return the number of items in the list
/// </summary>
/// <returns></returns>
public int Count()
{
LListNode <T> current = _head;
int count = 0;
while (current != null)
{
count++;
current = current.Next;
}
return(count);
}
/// <summary>
/// Add a node to the rear
/// </summary>
/// <param name="node"></param>
public void AddLast(LListNode <T> node)
{
if (_head == null)
{
_head = node;
_tail = node;
}
else
{
_tail.Next = node;
_tail = node;
}
}
/// <summary>
/// Add a LList Node to the front
/// </summary>
/// <param name="node"></param>
public void AddFirst(LListNode <T> node)
{
if (_head == null)
{
_head = node;
_tail = node;
}
else
{
node.Next = _head;
_head = node;
}
}
/// <summary>
/// Add a node before specific node
/// </summary>
/// <param name="node"></param>
/// <param name="newNode"></param>
public void AddBefore(LListNode <T> node, LListNode <T> newNode)
{
if (node == _head)
{
AddFirst(newNode);
return;
}
var current = _head;
while (current.Next != node)
{
current = current.Next;
}
newNode.Next = node;
current.Next = newNode;
}
/// <summary>
/// Override from System.Object, convert the list to a string
/// </summary>
/// <returns></returns>
public override string ToString()
{
LListNode <T> current = _head;
string result = "";
while (current != null)
{
result += current.Value.ToString();
if (current.Next != null)
{
result += ",";
}
current = current.Next;
}
return(result);
}
/// <summary>
/// remove the head of list
/// </summary>
/// <returns></returns>
public bool RemoveFirst()
{
if (_head == null)
{
return(false);
}
if (_head.Next == null)
{
_head = null;
_tail = null;
return(true);
}
_head = _head.Next;
return(true);
}
/// <summary>
/// Find the last appearance of a value and return the node
/// </summary>
/// <param name="value"></param>
/// <returns></returns>
public LListNode <T> FindLast(T value)
{
if (_head == null)
{
return(null);
}
var current = _head;
LListNode <T> buffer = null;
while (current != null)
{
if (EqualityComparer <T> .Default.Equals(current.Value, value))
{
buffer = current;
}
current = current.Next;
}
return(buffer);
}
/// <summary>
/// Remove specific node
/// </summary>
/// <param name="node"></param>
/// <returns></returns>
public bool Remove(LListNode <T> node)
{
if (_head == null)
{
return(false);
}
if (_head == _tail && ReferenceEquals(_head, node))
{
this.Clear();
return(true);
}
else if (ReferenceEquals(_head, node))
{
this.RemoveFirst();
return(true);
}
else if (ReferenceEquals(_tail, node))
{
this.RemoveLast();
return(true);
}
else
{
var prev = _head;
while (prev.Next != null)
{
if (ReferenceEquals(prev, node))
{
prev.Next = prev.Next.Next;
return(true);
}
prev = prev.Next;
}
return(false);
}
}
/// <summary>
/// Clear this LList
/// </summary>
public void Clear()
{
_head = null;
_tail = null;
}
/// <summary>
/// Add a value as a node before specific node
/// </summary>
/// <param name="node"></param>
/// <param name="value"></param>
public void AddBefore(LListNode <T> node, T value)
{
var newNode = new LListNode <T>(value);
AddBefore(node, newNode);
}
/// <summary>
/// Add a value as a node after a specific node
/// </summary>
/// <param name="node"></param>
/// <param name="value"></param>
public void AddAfter(LListNode <T> node, T value)
{
var newNode = new LListNode <T>(value);
AddAfter(node, newNode);
}
/// <summary>
/// Add a value as a node to the rear
/// </summary>
/// <param name="value"></param>
public void AddLast(T value)
{
var node = new LListNode <T>(value);
AddLast(node);
}