/// <summary>
/// Use Hashtable to store the copyList object as we create while going next on originalLL. Use hashtable to restore prev(random) pointer
/// Time O(n) Space O(n)
/// </summary>
/// <param name="linkedList"></param>
/// <param name="copyList"></param>
public static void CloneLinkedList(DoublyLinkedList linkedList, DoublyLinkedList copyList)
{
Hashtable linkedObj = new Hashtable();
DoublyLinkedListNode llNode = linkedList.Head;
DoublyLinkedListNode copyPrevNode = new DoublyLinkedListNode(0);
while (llNode != null)
{
DoublyLinkedListNode copyNode = new DoublyLinkedListNode(llNode.data);
linkedObj.Add(copyNode.data, copyNode);
if (copyList.Head == null)
{//Add first Element
copyPrevNode = copyNode;
//copyPrevNode.next =
copyList.AddNode(copyNode);
}
else
{//
copyPrevNode.next = copyNode;
copyPrevNode = copyNode;
}
llNode = llNode.next;
}
llNode = linkedList.Head;
DoublyLinkedListNode copyLlNode = copyList.Head;
while (llNode != null && copyLlNode != null)
{
DoublyLinkedListNode copyNode = (DoublyLinkedListNode)linkedObj[llNode.prev.data];
copyLlNode.prev = copyNode;
llNode = llNode.next;
copyLlNode = copyLlNode.next;
//copyList.AddBefore(llNode, copyNode);
}
}
public static void CloneLinkedListWithNextAndRandomPointerMain()
{
DoublyLinkedList ll = new DoublyLinkedList();
DoublyLinkedListNode node1 = new DoublyLinkedListNode(1);
DoublyLinkedListNode node2 = new DoublyLinkedListNode(2);
DoublyLinkedListNode node3 = new DoublyLinkedListNode(3);
DoublyLinkedListNode node4 = new DoublyLinkedListNode(4);
node1.next = node2;
node1.prev = node3;
node2.next = node3;
node2.prev = node4;
node3.next = node4;
node3.prev = node1;
node4.prev = node2;
ll.AddNode(node1);
ll.PrintLL();
DoublyLinkedList copyLL = new DoublyLinkedList();
CloneLinkedList(ll, copyLL);
copyLL.PrintLL();
copyLL = new DoublyLinkedList();
CloneLinkedListInConstantSpace(ll, copyLL);
copyLL.PrintLL();
}
