public DoubleListNode Reverse(DoubleListNode d)
{
for (var node = d; node != null; node = node.prev)
{
var swap = node.prev;
node.prev = node.next;
node.next = swap;
}
return(d);
}
public DoubleListNode Init(int n)
{
DoubleListNode node = null;
for (int i = 1; i <= n; i++)
{
var prev = node;
node = new DoubleListNode(i, node, null);
if (prev != null)
{
prev.prev = node;
}
}
return(node);
}
public DoubleListNode InsertInPosition(DoubleListNode d, int position, int val)
{
int i = 0;
for (var node = d; node != null; node = node.next, i++)
{
if (i == position)
{
var backup = node.next;
node.next = new DoubleListNode(val, null, null);
node.next.next = backup;
node.next.prev = node;
backup.prev = node.next;
}
}
return(d);
}
public void Print(DoubleListNode d)
{
var backup = d;
DoubleListNode lastNode = null;
Console.WriteLine();
Console.WriteLine("Forward");
while (backup != null)
{
Console.Write(backup.val + "->");
if (backup.next == null)
{
lastNode = backup;
}
backup = backup.next;
}
Console.WriteLine("\nBackward");
while (lastNode != null)
{
Console.Write(lastNode.val + "->");
if (lastNode.prev == null)
{
backup = lastNode;
}
lastNode = lastNode.prev;
}
Console.WriteLine();
Console.WriteLine("Forward");
while (backup != null)
{
Console.Write(backup.val + "->");
if (backup.next == null)
{
lastNode = backup;
}
backup = backup.next;
}
}
public DoubleListNode(int val, DoubleListNode next, DoubleListNode prev)
{
this.val = val;
this.next = next;
this.prev = prev;
}