typedef struct Node
{
  int data;
  struct Node* next;
}node, *pLinkedList;

bool isHuiWen(pLinkedList head)
{
  if (head == NULL || head->next == NULL)
    return true;
  pLinkedList right = head->next;//保存中间节点的下一个节点(若为偶数则为偏右的中间节点)
  pLinkedList cur = head;      //快指针
  while (cur->next != NULL && cur->next->next != NULL)
  {
    right = right->next;
    cur = cur->next->next;
  }
  //当链表总结点个数为奇数情况时：
  if (cur->next != NULL && cur->next->next == NULL)
    right = right->next;
  //将链表右边的节点放入一个栈中
  stack<pLinkedList>* s = new stack<pLinkedList>();
  while (right != NULL)
  {
    s->push(right);
    right = right->next;
  }
  //比较链表左右两边节点是否相等
  while (!s->empty())
  {
    if (head->next->data != s->top()->data)
      return false;
    s->pop();
    head = head->next;
  }
  return true;
}