public void AddItem(int insertValue, Position position, int index = 0)
{
DoubleNodes node = new DoubleNodes();
node.value = insertValue;
AddtoList(node, position, index);
}
public void PrintAllReverse()
{
DoubleNodes current = Tail;
Console.WriteLine("PRINT ALL DOUBLE LINKED LIST IN REVERSE");
while (current != null)
{
Console.WriteLine(current.value);
current = current.PreviousValue;
}
}
public void PrintAllList()
{
DoubleNodes current = Head;
Console.WriteLine("PRINT ALL DOUBLE LINKED LIST");
while (current != null)
{
Console.WriteLine(current.value);
current = current.NextValue;
}
}
private void RemoveFromList(Position removePosition, int index)
{
if (removePosition == Position.BEGIN)
{
var nextItemAfterHead = Head.NextValue;
nextItemAfterHead.PreviousValue = null;
Head = nextItemAfterHead;
listCount--;
}
else if (removePosition == Position.END)
{
for (DoubleNodes node = Head; node != null; node = node.NextValue)
{
if (node.NextValue.NextValue == null)
{
Tail = node;
node.NextValue = null;
listCount--;
break;
}
}
}
else if (removePosition == Position.MIDDLE)
{
if (index <= listCount)
{
int counter = 0;
DoubleNodes current = Head;
while (current != null)
{
if (counter + 1 == index)
{
var movingNode = current.NextValue.NextValue;
current.NextValue = movingNode;
movingNode.PreviousValue = current;
break;
}
current = current.NextValue;
counter++;
}
}
else
{
Console.WriteLine("Incorrect Index");
}
}
}
private void AddtoList(DoubleNodes item, Position addPosition, int index)
{
if (Head == null)
{
Head = item;
Tail = item;
listCount = 1;
}
else
{
if (addPosition == Position.END)
{
DoubleNodes previousNode = null;
for (DoubleNodes node = Head; node != null; node = node.NextValue)
{
if (node.NextValue == null)
{
item.PreviousValue = node;
node.NextValue = item;
Tail = item;
listCount++;
}
}
}
else if (addPosition == Position.BEGIN)
{
var oldHeadItem = Head;
oldHeadItem.PreviousValue = item;
item.NextValue = oldHeadItem;
Head = item;
listCount++;
}
else if (addPosition == Position.MIDDLE)
{
if (index <= listCount)
{
int counter = 0;
DoubleNodes current = Head;
while (current != null)
{
if (counter + 1 == index)
{
var movingNode = current.NextValue;
movingNode.PreviousValue = item;
item.PreviousValue = current;
item.NextValue = movingNode;
current.NextValue = item;
break;
}
current = current.NextValue;
counter++;
}
}
else
{
Console.WriteLine("Incorrect Index");
}
}
}
}
