#include <iostream>
#include <cstdlib>
#include <ctime>

using namespace std;

//鏈表節(jié)點(diǎn)類(lèi)
class Node
{
private:
  int m_data;
  Node* m_next;

  Node(Node&) {}    //copy constructor is not allowed

public:
  explicit Node(int val = 0) : m_data(val), m_next(NULL) {}
  int getData() const { return m_data; }
  void setData(int val) { m_data = val; }
  Node* getNext(void) const { return m_next; }
  void setNext(Node* p) { m_next = p; }
};

//鏈表
class MyList
{
private:
  Node* m_head;  //pionter to the first node of the list
  Node* m_tail;  //poinoer to the last node of the list

  MyList(MyList&) {}
public:
  explicit MyList() : m_head(NULL), m_tail(NULL) {}
  void addNode(Node* pNode);
  void show(void) const;
  void reverse(void);
  void clean(void);
};

void MyList::addNode(Node* pNode)
{
  if (m_head)
  {
    m_tail->setNext(pNode);
    m_tail = pNode;
  }
  else    //blank list
  {
    m_head = pNode;
    m_tail = pNode;
  }
}

void MyList::show(void) const
{
  Node* pNode = m_head;
  while (pNode)
  {
    std::cout << pNode->getData() << "  ";
    pNode = pNode->getNext();
  }
}

void MyList::reverse(void)
{
  Node* preNode = NULL;    //下面游標(biāo)的前一個(gè)
  Node* pNode ;    //指向每一個(gè)節(jié)點(diǎn)，相當(dāng)于游標(biāo)
  Node* afterNode;    //上面游標(biāo)的上一個(gè)

  for (pNode = m_head; pNode != NULL; pNode = afterNode)  //這里的每次循環(huán)對(duì)應(yīng)一個(gè)節(jié)點(diǎn)，本質(zhì)上和數(shù)組原理差不多
  {
    afterNode = pNode->getNext();
    pNode->setNext(preNode);
    preNode = pNode;
  }

  pNode = m_head;  //交換頭尾指針
  m_head = m_tail;
  m_tail = pNode;
}

void MyList::clean(void)
{
  if (m_head)
  {
    Node* pNode = m_head;
    Node* pTemp;
    while (pNode)
    {
      pTemp = pNode->getNext();
      delete pNode;
      pNode = pTemp;
    }

    m_head = m_tail = NULL;
  }
}

int main(void)
{
  MyList listHead;

  srand((unsigned)time(NULL));
  for (int i = 0; i < 9; i++)
  {
    int temp = rand() % 50;
    Node* pNode = new Node(temp);
    listHead.addNode(pNode);
  }
  listHead.show();

  listHead.reverse();
  cout << endl;
  listHead.show();
  listHead.clean();
  listHead.show();
  
  system("pause");
}