/// <summary>
/// Returns a number of elements as specified by countOfElements, starting from the specified index.
/// </summary>
/// <param name="index">Starting index.</param>
/// <param name="countOfElements">The number of elements to return.</param>
/// <returns>Doubly-Linked List of elements</returns>
public virtual DLinkedList <T> GetRange(int index, int countOfElements)
{
DLinkedListNode <T> currentNode = null;
DLinkedList <T> newList = new DLinkedList <T>();
// Handle Index out of Bound errors
if (Count == 0)
{
return(newList);
}
if (index < 0 || index > Count)
{
throw new IndexOutOfRangeException();
}
// Decide from which reference to traverse the list, and then move the currentNode reference to the index
// If index > half then traverse it from the end (_lastNode reference)
// Otherwise, traverse it from the beginning (_firstNode refrence)
if (index > (Count / 2))
{
currentNode = this._lastNode;
for (int i = (Count - 1); i > index; --i)
{
currentNode = currentNode.Previous;
}
}
else
{
currentNode = this._firstNode;
for (int i = 0; i < index; ++i)
{
currentNode = currentNode.Next;
}
}
// Append the elements to the new list using the currentNode reference
while (currentNode != null && newList.Count <= countOfElements)
{
newList.Append(currentNode.Data);
currentNode = currentNode.Next;
}
return(newList);
}
public virtual DLinkedList <T> GetRange(int index, int countOfElements)
{
DLinkedListNode <T> currentNode = null;
DLinkedList <T> newList = new DLinkedList <T>();
if (Count == 0)
{
return(newList);
}
if (index < 0 || index > Count)
{
throw new IndexOutOfRangeException();
}
if (index > (Count / 2))
{
currentNode = this._lastNode;
for (int i = (Count - 1); i > index; --i)
{
currentNode = currentNode.Previous;
}
}
else
{
currentNode = this._firstNode;
for (int i = 0; i < index; ++i)
{
currentNode = currentNode.Next;
}
}
while (currentNode != null && newList.Count <= countOfElements)
{
newList.Append(currentNode.Data);
currentNode = currentNode.Next;
}
return(newList);
}