IsCycleList Check if a singly linked list is a cycle linked list.
If the list is a cycle linked list, the method return the head node of the cycle, or else return null;
please find bug below.
 
struct pLinkedList
{
  pLinkedList* Next;
}
 
pLinkedList IsCycleList(LinkedList *pHead)
{
  pLinkedList* pStart,PCur;
  while(pCur!=null)
  {
    for(;;)
    {
      if (pStart==pCur->Next)
        return pStart;
      pStart=pStart->Next;
    }
    pCur=pCur->Next;
  }
  return pStart;
}