static LLNode <int> DetectLoop(LLNode <int> head)
{
var p = head;
var q = head;
while (p != null && q != null && q.Next != null)
{
p = p.Next;
q = q.Next.Next;
if (p == q)
{
//var loop = p;
q = head;
while (p == q)
{
p = p.Next;
q = q.Next;
}
return(p);
}
}
return(null);
}
public LLNode(T data)
{
this.Data = data;
this.Previous = this.Next = null;
}