public void Swap(DoubleLink <T> a, DoubleLink <T> b)
{
if (a == b)
{
throw new Exception("Cannot Swap!");
}
DoubleLink <T> beforeA = a.Previous;
DoubleLink <T> afterA = a.Next;
DoubleLink <T> beforeB = b.Previous;
DoubleLink <T> afterB = b.Next;
b.Delete();
b.InsertAfter(a);
a.Delete();
if (beforeB == null)
{
a.InsterBefore(afterB);
}
else
{
if (afterA == b)
{
a.InsertAfter(b);
}
else
{
a.InsertAfter(beforeB);
}
}
}
public DoubleLink <T> FindBy(T value)
{
DoubleLink <T> temp = new DoubleLink <T>(value);
if (this.Value.Equals(value))
{
temp = this;
}
return(temp);
}
//T IEnumerator<T>.Current => throw new NotImplementedException();
public bool MoveNext()
{
//bool result = _node != null;
if (_node != null)
{
position++;
_node = _node.Next;
}
//return result;
return(position <= number);
}
public void InsterBefore(DoubleLink <T> node)
{
if (node.Previous == null)
{
this.Previous = null;
this.Next = node;
node.Previous = this;
}
else
{
this.Previous = node.Previous;
this.Next = node;
node.Previous = this;
this.Previous.Next = this;
}
}
public void InsertAfter(DoubleLink <T> node)
{
if (node.Next == null)
{
node.Next = this;
this.Previous = node;
this.Next = null;
}
else
{
this.Next = node.Next;
this.Previous = node;
node.Next = this;
this.Next.Previous = this;
}
}
public void Delete()
{
if (this.IsHead && this.IsTail)
{
throw new Exception("Cannot delete last node!");
}
else if (this.IsTail)
{
DoubleLink <T> temp = this.Previous;
temp.Next = null;
}
else if (this.IsHead)
{
DoubleLink <T> temp = this.Next;
temp.Previous = null;
}
else
{
DoubleLink <T> temp1 = this.Previous;
DoubleLink <T> temp2 = this.Next;
temp1.Next = temp2;
temp2.Previous = temp1;
}
}
public DoubleLinkIEnumerable(DoubleLink <T> node)
{
number++;
_node = node;
position = -1;
}