C++实现双向链表

双向链表结构：

实现：

List.h#pragma once#include <iostream>#include <string>#include <assert.h>using namespace std;typedef int DateType;struct Node{public:    Node()        :_pNext(NULL)        , _pPrev(NULL)        , _data(NULL)    {}    Node(const DateType &data)        :_pNext(NULL)        ,_pPrev(NULL)        ,_data(data)    {}    Node *_pNext;    Node *_pPrev;    DateType _data;};class List{public:    List()    {        _pHead = new Node;    }    void Display();  //打印    void PushBack(const DateType data);   //尾部插入    void PopBack();  //尾部删除    void PushFront(const DateType data);     //头部插入    void PopFront();      //头部删除    void Erase(Node *pos);   //删除指定节点    Node* Find(DateType &d);   //查询节点位置    void Insert(Node*pos, const DateType &data);  //指定地点插入    size_t Size();  //大小    void Clear();   //清空链表private:    Node *_pHead;};List.cpp#define _CRT_SECURE_NO_WARNINGS 1#include "List.h"void List::Display() {  //打印    assert(this);    Node *cur = _pHead->_pNext;    if (cur == NULL) {        cout << "空链" << endl;        return;    }    while (cur != NULL) {        cout << cur->_data << "--";        cur = cur->_pNext;    }    cout << endl;}void List::PushBack(const DateType data) {    assert(this);    Node *next = _pHead;    while ((next!=NULL)&&(next->_pNext != NULL)) {        next = next->_pNext;     //指向尾部    }    Node *cur = new Node(data);    next->_pNext = cur;    cur->_pPrev = next;    cur->_pNext = NULL;}void List::PopBack() {  //尾部删除    assert(this);    if (_pHead->_pNext == NULL){   //空链        cout << "已经是空链无法继续删除" << endl;        return;    }    Node *cur = _pHead;    while ((cur != NULL) && (cur->_pNext != NULL)) {        cur = cur->_pNext;     //指向尾部    }    Node *dest = cur->_pPrev;    delete cur;    dest->_pNext = NULL;}void List::PushFront(const DateType data){    //头部插入    assert(this);    if (_pHead->_pNext == NULL)    {        PushBack(data);        return;    }    Node *Data = new Node(data);    Node *cur = _pHead->_pNext;    _pHead->_pNext = Data;    Data->_pPrev = _pHead;    Data->_pNext = cur;    cur->_pPrev = Data;}void List::PopFront() {   //头部删除    assert(this);    if (_pHead->_pNext == NULL) {        cout << "已经是空链无法继续删除" << endl;        return;    }    Node*next = _pHead->_pNext->_pNext;    Node*cur = _pHead->_pNext;    delete cur;    if (next == NULL) {    //链中只有一个节点        _pHead->_pNext = NULL;        return;    }    _pHead->_pNext = next;    next->_pPrev = _pHead;}void List::Erase(Node *pos) {   //删除指定节点    assert(this);    Node *cur = pos;    Node *next = pos->_pNext;    cur->_data = next->_data;    cur->_pNext = next->_pNext;    next->_pNext->_pPrev = cur;    delete next;}Node* List::Find(DateType &d) {   //查询节点位置    assert(this);    int pos = 0;    Node*cur = _pHead;    while (cur != NULL) {        if (cur->_data == d)            return cur;        cur = cur->_pNext;    }    return NULL;}void List::Insert(Node*pos, const DateType &data) {  //指定地点插入    assert(this);    Node *cur = pos->_pNext;    Node *dest = new Node(data);    pos->_pNext = dest;    dest->_pPrev = pos;    dest->_pNext = cur;    cur->_pPrev = dest;}size_t List::Size() {  //大小    int count = 0;    Node *cur = _pHead->_pNext;    while (cur != NULL) {        cur = cur->_pNext;    }    return count;}void List::Clear() {   //清空链表    assert(this);    if (_pHead == NULL) {        cout << "空链，无序继续清空" << endl;        return;    }    Node *cur = _pHead->_pNext;    Node *next = _pHead->_pNext->_pNext;    while (cur->_pNext != NULL) {        delete cur;        cur = next;        next = next->_pNext;    }}