模拟实现STL （双）链表

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#include<iostream>using namespace std;#include<assert.h>#include<list>#include<vector>template<class T>struct  _ListNode{    T _data;    _ListNode<T>* _next;    _ListNode<T>* _prev;    _ListNode(const T& x)        :_data(x)        ,_next(NULL)        , _prev(NULL)    {}};template<class T,class Ref,class Ptr>struct _ListIterator{    typedef _ListNode<T> Node;    typedef _ListIterator<T, Ref, Ptr> Self;    _ListIterator(Node *node)        :_node(node)    {}    Ref operator*()    {        return _node->_data;    }    bool operator==(const Self& s) const    {        return this->_node == s._node;    }    Self& operator++()    {        _node = _node->_next;        return *this;    }    Self& operator++(int)    {        Node* cur = _node;        _node = _node->_next;        return *cur;    }    Self& operator--()    {        _node = _node->_prev;        return *this;    }    Self& operator--(int)    {        Node* cur = _node;        _node = _node->_prev;        return *cur;    }    // it != l.End() // it.operator != (&it, l.End())     bool operator != (const Self& s) const    {        return this->_node != s._node;    }    Node* _node;};// 迭代器template<class T>class List{    typedef _ListNode<T> Node;public:    typedef _ListIterator<T, T&, T*> Iterator;    typedef _ListIterator<T, const T&, const T*> ConstIterator;    Node* GetNode(const T& x)    {        return new Node(x);    }    List()    {        _head = GetNode(T());        _head->_next = _head;        _head->_prev = _head;    }    Iterator Begin()    {        return Iterator(_head->_next);    }    ConstIterator Begin() const    {        return ConstIterator(_head->_next);    }    Iterator End()    {        return Iterator(_head);    }    ConstIterator End() const    {        return ConstIterator(_head);    }    void PushBack(const T& x)    {        Node* tail = _head->_prev;        Node* tmp = GetNode(x);        tail->_next = tmp;        tmp->_prev = tail;        tmp->_next = _head;        _head->_prev = tmp;    }    void PopBack()    {        if (_head->_next != _head)        {            Node* tail = _head->_prev;            Node* prev = tail->_prev;            delete tail;            prev->_next = _head;            _head->_prev = prev;        }    }    void PopFront()    {        if (_head->_next != _head)        {            Node *prev = _head->_next;            Node *cur = prev->_next;            delete prev;            _head->_next = cur;            cur->_prev = _head;        }    }    void PushFront(const T& x)    {        Node *tmp = GetNode(x);        Node *cur = _head->_next;        tmp->_next = cur;        tmp->_prev = _head;        _head->_next = tmp;        cur->_prev = tmp;    }    Iterator Find(const T& x)    {        if (_head->_next == _head)            return NULL;        else        {            Node *cur=_head->_next;            while (cur != _head)            {                if (cur->_data == x)                {                    return cur;                }                cur = cur->_next;            }            return NULL;        }    }    void Insert(Iterator pos,const T &x) // 指定元素前插入数据    {        assert(pos._node);        Node *tmp =GetNode(x);        Node *cur = _head->_next;        while (cur->_next != pos._node)        {            cur = cur->_next;        }        Node* prev = cur->_next;        tmp->_next = prev;        tmp->_prev = cur;        cur->_next = tmp;        prev->_prev = tmp;    }    Iterator Erase(Iterator pos)    {        assert(pos._node);        Node* cur = _head;        while (cur->_next != pos._node)        {            cur = cur->_next;        }        cur->_next = pos._node->_next;        pos._node->_next->_prev = cur;        delete pos._node;        pos._node = NULL;        return pos._node;    }protected:    Node* _head;};void PrintMyList(const List<int>& l1){    // [)    List<int>::ConstIterator it = l1.Begin();    while (it != l1.End())    {        //*it = 10;        cout << *it << " ";        ++it;    }    cout << endl;}void TestMyList() //执行结果:0 1 2 3{    List<int> l1;    l1.PushBack(1);    l1.PushBack(2);    l1.PushBack(3);    l1.PushBack(4);    l1.PushBack(5);    l1.PushFront(0);    l1.PopBack();    l1.PopFront();    l1.Insert(l1.Find(1), 0);    l1.Erase(l1.Find(4));    PrintMyList(l1);}void PrintVector(const vector<int>& v){    // 普通迭代器 -- 可读可写    // const 迭代器 -- 可读    // 反向迭代器  -- 反着遍历    // [begin, end)    vector<int>::const_iterator it = v.begin();    while (it != v.end())    {        /*  if (*it % 2)        {        cout<<*it<<" ";        }*/        //(*it)++;        cout << *it << " ";        ++it;    }    cout << endl;    vector<int>::const_reverse_iterator rIt = v.rbegin();//reverse    while (rIt != v.rend())    {        cout << *rIt << " ";        ++rIt;    }    cout << endl;}void TestVector(){    vector<int> v1;    v1.push_back(1);    v1.push_back(2);    v1.push_back(3);    v1.push_back(4);    PrintVector(v1);    vector<int> v2(3, 10);    // 类型--类似指针的一个对象 -- 智能指针    PrintVector(v2);}void PrintList(list<int>& l){    list<int>::const_iterator it = l.begin();    while (it != l.end())    {        cout << *it << " ";        //*it = 10;//const迭代器，不可修改        ++it;    }    cout << endl;}void TestList(){    list<int> l1;    l1.push_back(1);    l1.push_back(2);    l1.push_back(3);    l1.push_back(4);    PrintList(l1);    list<int> l2(5, 1);    PrintList(l2);}int main(){    //TestList();    TestMyList();    system("pause");    return 0;}
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