void Reverse(Node* head)
{
  Node* p,* q, *r=NULL;
  p = head->next;
  q = p->next;
  p->next = NULL;
  while (q)
  {
    r = q;
    q = q->next;
    r->next = p;
    p = r;
  }
  head->next = r;
}

void Reverse(Node* head,Node* p)//p=p->next
{
  if (p == NULL || p->next == NULL)//分别对应p为空表，p不为空表
  {
    head->next = p;
  }
  else
  {
    Node * pnext=p->next;
    Reverse(head,pnext);
    pnext->next = p;
    p->next = NULL;
  }
}

void Reverse_head(Node*head)
{
  Node* p, * q;
  p = head->next;
  head->next = NULL;
  while (p)
  {
    q = p->next;
    p->next = head->next;
    head->next = p;
    p = q;
  }
}

Node* Reverse(Node* head)
{
  Node* p, * q, * r=NULL;
  p = head;
  q = p->next;
  head->next = NULL;
  while (q)
  {
    r = q;
    q = q->next;
    r->next = p;
    p = r;
  }
  return r;
}

Node* Reversebyhead(Node*head)
{
  Node* p, * q;
  p = head->next;
  head->next = NULL;
  while (p)
  {
    q = p->next;
    p->next = head;
    head = p;
    p = q;
  }
  return head;
}