private DoubleLink <T> GetNodeAt(int pos)
{
if (pos >= m_Count || pos < 0)
{
throw new IndexOutOfRangeException("pos");
}
DoubleLink <T> currentNode = null;
// 最近的途径找到pos位置的节点
if (pos > m_Count / 2)
{
currentNode = m_Tail;
pos = m_Count - pos - 1;
while (pos-- > 0)
{
currentNode = currentNode.Prior;
}
}
else
{
currentNode = m_Head.Next;
while (pos-- > 0)
{
currentNode = currentNode.Next;
}
}
return(currentNode);
}
public void Clear()
{
m_Count = 0;
m_Tail = m_Head;
m_Head.Next = null;
m_Head.Prior = null;
}
public void InsertAt(T t, int pos)
{
if (pos > m_Count || pos < 0)
{
throw new IndexOutOfRangeException("pos");
}
if (m_Count == int.MaxValue)
{
throw new ArithmeticException();
}
DoubleLink <T> insertNode = new DoubleLink <T>(t);
if (pos == m_Count)
{
insertNode.Prior = m_Tail;
m_Tail.Next = insertNode;
m_Tail = insertNode;
m_Count++;
return;
}
DoubleLink <T> currentNode = GetNodeAt(pos);
insertNode.Prior = currentNode.Prior;
insertNode.Next = currentNode;
currentNode.Prior.Next = insertNode;
currentNode.Prior = insertNode;
m_Count++;
}
public DoubleLinkedList(T t)
: this()
{
m_Count = 1;
m_Head.Next = new DoubleLink <T>(t);
m_Tail = m_Head.Next;
m_Tail.Prior = m_Head;
}
public IEnumerator <T> GetEnumerator()
{
DoubleLink <T> currentNode = m_Head;
while ((currentNode = currentNode.Next) != null)
{
yield return(currentNode.Value);
}
}
public void RemoveAt(int pos)
{
if (pos == m_Count - 1)
{
m_Tail = m_Tail.Prior;
m_Tail.Next = null;
m_Count--;
return;
}
DoubleLink <T> currentNode = GetNodeAt(pos);
currentNode.Prior.Next = currentNode.Next;
currentNode.Next.Prior = currentNode.Prior;
m_Count--;
}
public int Find(T t)
{
DoubleLink <T> currentNode = m_Head;
int pos = 0;
while ((currentNode = currentNode.Next) != null)
{
if (currentNode.Value.Equals(t))
{
return(pos);
}
pos++;
}
return(-1);
}
public T GetPrevious()
{
if (m_Count == 0)
{
throw new IndexOutOfRangeException();
}
if (m_CurrentNode != null)
{
m_CurrentNode = m_CurrentNode.Prior;
m_CurrentIndex--;
}
if (m_CurrentNode == null || m_CurrentNode == m_Head)
{
m_CurrentNode = m_Tail;
m_CurrentIndex = m_Count - 1;
}
return(m_CurrentNode.Value);
}
public T GetNext()
{
if (m_Count == 0)
{
throw new IndexOutOfRangeException();
}
if (m_CurrentNode != null)
{
m_CurrentNode = m_CurrentNode.Next;
m_CurrentIndex++;
}
if (m_CurrentNode == null)
{
m_CurrentNode = m_Head.Next;
m_CurrentIndex = 0;
}
return(m_CurrentNode.Value);
}
public LoopLink(T t) : base(t)
{
m_CurrentNode = m_Head.Next;
m_CurrentIndex = 0;
}
public DoubleLinkedList()
{
m_Count = 0;
m_Head = new DoubleLink <T>();
m_Tail = m_Head;
}
