static void Main(string[] args)
{
ListNodeDLL node1 = new ListNodeDLL(1);
ListNodeDLL node2 = new ListNodeDLL(2);
ListNodeDLL node3 = new ListNodeDLL(3);
ListNodeDLL node4 = new ListNodeDLL(4);
node1.Next = node2;
node2.Next = node3;
node3.Next = node4;
node1.Random = node4;
node2.Random = node1;
node3.Random = node1;
//node4.Random = node1;
ListNodeDLL copy = CloneWithRandomPointer(node1);
//ListNodeDLL copy = CloneWithConstantSpace(node1);
//node1 = null;
//node2 = null;
//node3 = null;
//node4 = null;
Console.ReadLine();
}
public static ListNodeDLL CloneWithConstantSpace(ListNodeDLL head)
{
if (head == null)
{
return(null);
}
ListNodeDLL origCurrent = head;
while (origCurrent != null)
{
ListNodeDLL next = origCurrent.Next;
ListNodeDLL copiedNode = new ListNodeDLL(origCurrent.Data);
origCurrent.Next = copiedNode;
copiedNode.Next = next;
origCurrent = next;
}
origCurrent = head;
ListNodeDLL copyHead = origCurrent.Next;
while (origCurrent != null)
{
ListNodeDLL next = origCurrent.Next.Next;
if (origCurrent.Random != null)
{
origCurrent.Next.Random = origCurrent.Random.Next;
}
else
{
origCurrent.Next.Random = null;
}
if (origCurrent.Next.Next != null)
{
origCurrent.Next.Next = next.Next;
}
origCurrent.Next = next;
origCurrent = next;
}
return(copyHead);
}
private static ListNodeDLL CloneWithRandomPointer(ListNodeDLL head)
{
if (head == null)
{
return(null);
}
ListNodeDLL origCurrent = head;
ListNodeDLL cloneCurrent = null;
Dictionary <ListNodeDLL, ListNodeDLL> dictionary = new Dictionary <ListNodeDLL, ListNodeDLL>();
while (origCurrent != null)
{
dictionary.Add(origCurrent, new ListNodeDLL(origCurrent.Data));
origCurrent = origCurrent.Next;;
}
origCurrent = head;
while (origCurrent != null)
{
ListNodeDLL next = origCurrent.Next;
cloneCurrent = dictionary[origCurrent];
cloneCurrent.Next = origCurrent.Next != null ? dictionary[origCurrent.Next] : null;
cloneCurrent.Random = origCurrent.Random != null ? dictionary[origCurrent.Random] : null;
origCurrent = next;
}
//change start
//// Below code also works fine
//foreach (var pair in dictionary)
//{
// var orig = pair.Key;
// var copy = pair.Value;
// copy.Next = orig.Next != null ? dictionary[orig.Next] : null;
// copy.Random = orig.Random != null ? dictionary[orig.Random] : null;
//}
//change end
return(dictionary[head]);
}
