public T RemoveLast()
{
T value = default(T);
// If no items throw error
if (Count == 0)
{
throw new InvalidOperationException("No items to remove.");
}
if (Count == 1)
{
value = Tail.Value;
Head = null;
Tail = null;
}
else
{
value = Tail.Value;
Tail = Tail.Previous;
Tail.Next = null;
}
Count--;
return(value);
}
public T RemoveFirst()
{
T value = default(T);
// If no items throw error
if (Count == 0)
{
throw new InvalidOperationException("No items to remove.");
}
value = Head.Value;
if (Count == 1)
{
Head = null;
Tail = null;
}
else
{
var current = Head;
Head = (DoubleLinkListNode <T>)Head.Next;
current = null;
}
Count--;
return(value);
}
public void AddFirst(T value)
{
DoubleLinkListNode <T> node = new DoubleLinkListNode <T>()
{
Value = value
};
// if first
if (Count == 0)
{
Head = node;
Tail = node;
}
else
{
node.Next = Head;
Head.Previous = node;
Head = node;
}
Count++;
}
public void AddLast(T value)
{
DoubleLinkListNode <T> node = new DoubleLinkListNode <T>()
{
Value = value
};
// If first
if (Count == 0)
{
Head = node;
Tail = node;
}
else
{
Tail.Next = node;
node.Previous = Tail;
Tail = node;
}
Count++;
}
public bool Remove(T item)
{
// If no items throw error
if (Count == 0)
{
throw new InvalidOperationException("No items to remove.");
}
DoubleLinkListNode <T> current = Head;
while (current != null)
{
if (current.Value.CompareTo(item) == 0)
{
// if First
if (current.Previous == null)
{
RemoveFirst();
return(true);
}
// if Last
if (current == Tail)
{
RemoveLast();
return(true);
}
// if in between
current.Previous.Next = current.Next;
((DoubleLinkListNode <T>)current.Next).Previous = current.Previous;
current = null;
Count--;
return(true);
}
current = (DoubleLinkListNode <T>)current.Next;
}
return(false);
}
