c++——双向循环链表常见操作

来源：互联网发布：巴黎散步道知乎编辑：程序博客网时间：2024/05/29 09:53

双向循环链表示意图：
这里写图片描述

代码：

#ifndef __LIST_H__#define __LIST_H__#include <stdio.h>#include<iostream>#include<assert.h>using namespace std; class Listnode{public:    int  _data;     Listnode * prev;  //前续指针     Listnode* next;  //后续指针     Listnode(Listnode* _next = NULL,Listnode*_prev = NULL)        : next(_next)        , prev(_prev)    {}     Listnode(const int data, Listnode* _next = NULL, Listnode*_prev = NULL)        :_data(data)        , prev(_prev)        , next(_next)    { }        void Setdata(int  data)    {            this->_data = data;    }}; class List :public Listnode { public:     List();//构造函数     ~List();//析构函数     bool Empty()  //   清空     {         return this->size == 0;     }     int sizelist()     {         return this->size;     }     void pushfront(const int& data);  //头插     void pushback(const int& data);   //尾插     void push_val(const int& data, int pos);  //任意位置插入     void popfront();  //头删     void popback();//尾删     void pop_val(int pos);//任意位置删除     Listnode* findnode(int pos);//指定位置查找     void reserse();//链表的逆置     void sortlist();//链表排序     void printlist(); private:     Listnode* head;  //头指针     Listnode* tail;   //尾指针     int size; }; int Getpushfront();   //异常警告 int Getpush_val(); int Getpopfront(); int Getpop_val(); Listnode* Condata(const int& data);#endif

#include "list.h"Listnode* Condata(const int& data)//构造一个新的节点{    Listnode*newnode = new Listnode(data);    if (newnode == NULL)    throw Getpushfront();  //抛出异常    return newnode;}Listnode* List::findnode(int pos)//得到pos位置的节点{    Listnode* tempnode = head->next;    for (int i = 1; i < pos; i++)     {        tempnode = tempnode->next;    }    return tempnode;}List::List()//构造函数构造头结点{    head = tail = new Listnode;    head->next = tail;    tail->prev = head;    tail->next = head;    head->prev = tail;    size = 0;}List::~List(){    Listnode*pdel;    Listnode*ptemp;    pdel = head->next;  //找到第一个节点    while (pdel != head)  //循环头删    {        ptemp = pdel->next;//定义两个指针变量 更好释放        head->next = ptemp;        ptemp->prev = head;        //head->next = pdel->next      一个变量释放        //pdel->next->prev = head        delete pdel;        pdel = ptemp;       }    delete head;}void List::pushfront(const int& data)//头插{    Listnode* newnode = Condata(data);    if (size == 0)    //本来没有节点    {        newnode->next = tail;        tail->prev = newnode;        head->next = newnode;        newnode->prev = head;        size++;          return ;    }    newnode->next = head->next;    head->next = newnode;    newnode->next->prev = newnode;    newnode->prev = head;    size++;}void List::pushback(const int& data)   //尾插{    Listnode* newnode = Condata(data);    if (size == 0)          {        pushfront(data);  //        return;    }    tail->prev->next = newnode;    newnode->prev = tail->prev;    newnode->next = tail;    tail->prev = newnode;    size++;}void List::push_val(const int& data, int pos) //任意位置插入{    Listnode* newnode = Condata(data);    if (pos>(size+1))    {        throw Getpush_val();//抛出异常        return;    }    if ( (pos==1)||(pos == (size + 1)))   //头插或尾插    {        if (pos== 1)            List::pushfront(data);        else        List::pushback(data);        return;    }    Listnode* tempnode = findnode(pos);//找到这个位置的节点    newnode->next = tempnode;              //插入操作    tempnode->prev->next = newnode;    newnode->prev = tempnode;    tempnode->prev = newnode;    /*Listnode* _next =tempnode;    //定义两个变量进行插入操作    Listnode* _prev = tempnode->prev;    _prev->next = newnode;    newnode->next = _next;    newnode->prev = _prev;    _next->prev = newnode;    */    size++;}void List::popfront() //头删{    if (size == 0)    {        throw  Getpopfront();        return;    }    Listnode* tempnode = head->next;    head->next = head->next->next;    delete(tempnode);    tempnode = NULL;    size--;}void List::popback()//尾删{    Listnode* tempnode = tail->prev;    tempnode->prev->next = tail;    tail->prev = tempnode->prev;    delete(tempnode);    tempnode = NULL;        size--;}void List::printlist()   //打印链表{    Listnode*tempnode = head->next;    if (size == 0)    {        cout << "链表为空" << endl;        return;    }    for (int i =0;i<size;i++)    {        printf("%2d " ,tempnode->_data);        tempnode = tempnode->next;    }    printf("\n");}void List::pop_val(int pos)//任意位置删除{    if (pos<0 || pos>size)        throw Getpop_val();  //抛出异常    if (pos == 1 || pos == size)        return pos == 1 ? List::popfront() : List::popback();    Listnode* tempnode = findnode(pos);    tempnode->prev->next = tempnode->next;    tempnode->next->prev = tempnode->prev;    delete(tempnode);    tempnode = NULL;    size--;}void List::reserse()  //逆置{    Listnode* left = head->next;    Listnode* right = tail->prev;    while (left != right)    {        int data = left->_data;        left->_data = right->_data;        right->_data = data;        left = left->next;        right = right->prev;    }   }void List::sortlist ()  //排序{     Listnode*i_tempnode = head->next;    for (int i = 0; i < size; i++)    {        Listnode* j_tempnode = i_tempnode->next;        for (int j = 0; j < size - i - 1; j++)        {            if (i_tempnode->_data < j_tempnode->_data)            {                int data = j_tempnode->_data;                j_tempnode->_data = i_tempnode->_data;                i_tempnode->_data = data;            }            j_tempnode = j_tempnode->next;        }        i_tempnode = i_tempnode->next;    }}int Getpushfront()  {    cout << "开辟节点失败" << endl;    return  0;}int Getpush_val(){    cout << "任意插入位置非法" << endl;    return 0;}int Getpopfront(){    cout << "链表为空，删除节点失败" << endl;    return 0;}int Getpop_val(){    cout << "删除位置不合法" << endl;    return  0;}

测试代码：

#include "list.h"int main(){    List list;    list.pushfront(5);    list.pushfront(4);    /*list.pushfront(3);    list.pushfront(2);    list.pushfront(1);    list.pushback(9);    list.pushback(8);    list.pushback(7);*/    list.pushback(6);    /*list.printlist();    list.push_val(11, 4);    list.push_val(11, 1);    list.printlist();*/    ///*list.push_val(11, 30);*/    //list.printlist();    //list.popfront();    //list.printlist();    //list.popback();    //list.printlist();    //list.pop_val(1);    //list.printlist();    list.pushback(9);    list.pushback(1);    list.printlist();    /*list.reserse();    list.printlist();*/    list.sortlist();    list.printlist();return 0;}

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