单链表

双向链表enter link description here
单链表是一种链式存取的数据结构，用一组地址任意的存储单元存放线性表中的数据元素。链表中的数据是以结点来表示的，每个结点的构成：元素(数据元素的映象) + 指针(指示后继元素存储位置)，元素就是存储数据的存储单元，指针就是连接每个结点的地址数据。
具体实现如下

#pragma once#include<iostream>#include<assert.h>using namespace std;typedef int DataType;//链表中的数据struct SListNode{    SListNode* _next;    DataType _data;    SListNode(DataType x)        :_data(x)        , _next(NULL)    {}};class SList{    typedef SListNode Node;public:    //构造    SList()        :_head(NULL)        ,_tail(NULL)    {        ;    }    SList(const SList& s)    {        /*Node* s_tmp = s._head;        if (_head == NULL)        {            _head = _tail = new Node(s_tmp->_data);            s_tmp = s_tmp->_next;        }        while (s_tmp)        {            _tail->_next = new Node(s_tmp->_data);            _tail = _tail->_next;        }*/        Copy(s);    }    //传统法    /*SList& operator=(const SList& s)    {        Node* s_tmp = s._head;        if (_head == NULL)        {            _head = _tail = new Node(s_tmp->_data);            s_tmp = s_tmp->_next;        }        while (s_tmp)        {            _tail->_next = new Node(s_tmp->_data);            _tail = _tail->_next;        }        return *this;    }*/    //现代法    SList& operator=(SList s)    {        swap(_head, s._head);        swap(_tail, s._tail);        return *this;    }    //析构    ~SList()    {        Node* cur = _head;        if (cur)        {            Node* next = cur->_next;            delete cur;            cur = next;        }        _head = _tail = NULL;    }    //尾插    void PushBack(DataType x)    {        if (_head == NULL)        {            _head = _tail = new Node(x);        }        else        {            _tail->_next = new Node(x);            _tail = _tail->_next;        }    }    //尾删    void PopBack()    {        if (_head == NULL)        {            cout << "没有数据可以删除" << endl;        }        else if (_head->_next == NULL)        {            delete _head;            _head = _tail = NULL;        }        else        {            Node* tmp = _head;            while (tmp->_next != _tail)            {                tmp = tmp->_next;            }            delete _tail;            _tail = tmp;            _tail->_next = NULL;        }    }    //头插    void PushFront(DataType x)    {        if (_head = NULL)        {            _head = _tail = new Node(x);        }        else        {            Node* prev = new Node(x);            prev->_next = _head;            _head = prev;        }    }    //头删-------删除数据记得要delete，不然导致内存泄漏    void PopFront()    {        if (_head == NULL)        {            cout << "没有数据可以删除" << endl;        }        else if(_head->_next == NULL)        {            delete _head;            _head = _tail = NULL;        }        Node* cur = _head;        _head = _head->_next;        delete cur;        cur = NULL;    }    // 插入一个节点在pos的前面     void Insert(Node* pos, DataType x)    {        assert(pos);        if (_head == pos)        {            PushFront(x);        }        else        {            Node* head = _head;            while (head->_next != pos)            {                head = head->_next;            }            Node* tmp = new Node(x);            head->_next = tmp;            tmp->_next = pos;        }    }    //删除pos位置的数据    void Erase(Node* pos)    {        if (_head == pos)        {            PopFront();        }        else if (_tail == pos)        {            PopBack();        }        else        {            Node* head = _head;            while (head->_next != pos)            {                head = head->_next;            }            head->_next = pos->_next;            delete pos;        }    }    //查找    Node* Find(DataType x)    {        Node* cur = _head;        while (cur)        {            if (cur->_data == x)            {                return cur;            }                cur = cur->_next;        }        return NULL;    }    //拷贝  拷贝构造就可以复用这个函数    void Copy(const SList& s)    {        Node* cur = s._head;        while (cur)        {            PushBack(cur->_data);            cur = cur->_next;        }    }    //    void Print()    {        Node* cur = _head;        while (cur)        {            cout << cur->_data << " ";            cur = cur->_next;        }        cout << endl;    }private:    Node* _head;//头结点    Node* _tail;//尾结点};