【C++】实现双向链表的所有操作，包括逆置双链表(三种方法)

来源：互联网发布：哈布斯堡知乎编辑：程序博客网时间：2024/05/19 16:38

建立源文件List.cpp

include "List.h"int main(){    Test();    system("pause");    return 0;}

建立头文件List.h

#ifndef __LISH_H__#define __LISH_H__#include<iostream>using namespace std;typedef int DataType;struct ListNode{    ListNode(DataType x)    :_next(NULL)    , _prev(NULL)    , _data(x)    {}    ListNode* _next;    ListNode* _prev;    DataType _data;};class List{public:    List()        :_head(NULL)        ,_tail(NULL)    {}    List(const List& s)        :_head(NULL)        , _tail(NULL)    {        ListNode* cur = s._head;        while (cur)        {            this->PushBack(cur->_data);            cur = cur->_next;        }    }    List& operator= (const List& s)    {        //先删除节点，再插入节点        if (&s != this)        {            ListNode* pcur = _head;            while (pcur)            {                ListNode* del = pcur;                pcur = pcur->_next;                delete del;                del = NULL;            }            ListNode* cur = s._head;            while (cur)            {                this->PushBack(cur->_data);                cur = cur->_next;            }        }        return *this;    }    ~List()    {        ListNode* cur = _head;        while (cur)        {            ListNode* del = cur;            cur = cur->_next;            delete del;            del = NULL;        }    }    //尾插    void PushBack(DataType x)    {        //分：0节点   1、多节点两种情况        if (_head == NULL)        {            _head = new ListNode(x);            _tail = _head;            _tail->_next = NULL;        }        else        {            ListNode* cur = new ListNode(x);            _tail->_next = cur;            cur->_prev = _tail;            _tail = cur;            _tail->_next = NULL;        }    }    //尾删    void PopBack()    {        if (_head == _tail)        {            if (_head != NULL)            {                delete _head;                _head = NULL;                _tail = NULL;            }            else            {                return;            }        }        else        {            ListNode* prev = _tail->_prev;            delete _tail;            _tail = NULL;            _tail = prev;            _tail->_next = NULL;        }    }    //头插    void PushFront(DataType x)    {        if (_head == NULL)        {            PushBack(x);        }        else        {            ListNode* index = new ListNode(x);            index->_next = _head;            _head->_prev = index;            _head = index;            _head->_prev = NULL;        }    }   //头删    void PopFront()    {        if (_head == _tail)        {            PopBack();                    }        else        {            ListNode* del = _head;            ListNode* next = _head->_next;            _head = next;            _head->_prev = NULL;            delete del;            del = NULL;        }    }        //插入元素    void Insert(size_t pos, DataType x)    {        //分：是尾插   不是尾插    两种情况        ListNode* cur = _head;        while (--pos)        {                        cur = cur->_next;                }        if (cur == _tail)        {            PushBack(x);        }        else        {            ListNode* index = new ListNode(x);            ListNode* prev = cur->_prev;            index->_next = cur;            cur->_prev = index;            prev->_next = index;            index->_prev = prev;        }    }    //查找元素    ListNode* Find(DataType x)    {        ListNode* cur = _head;        while (cur)        {            if (cur->_data == x)            {                 return cur;            }            cur = cur->_next;        }        return NULL;    }    //删除元素    void Erase(ListNode* pos)    {        if (pos == _head)        {            PopFront();        }        else if (pos == _tail)        {            PopBack();        }        else        {            ListNode* prev = pos->_prev;            ListNode* next = pos->_next;            prev->_next = next;            next->_prev = prev;            delete pos;            pos = NULL;        }    }        //逆置方法一：从两头走，交换数据    /*void Reverse()    {        ListNode* begin = _head;        ListNode* end = _tail;        while (!((begin == end) || (end->_next == begin)))        {            swap(begin->_data, end->_data);            begin = begin->_next;            end = end->_prev;        }    }*/    //逆置方法二：交换节点的前驱和后继    /*void Reverse()    {        ListNode* cur = _head;        while (cur)        {            swap(cur->_prev, cur->_next);            cur = cur->_prev;        }        swap(_head, _tail);    }*/        //逆置方法三：摘节点，头插该节点    void Reverse()    {        ListNode* cur = _head;        ListNode* newhead = NULL;        while (cur)        {            ListNode* tmp = cur;            cur = cur->_next;            if (newhead == NULL)            {                newhead = tmp;                newhead->_next = NULL;                newhead->_prev = NULL;                _head = _tail = newhead;            }            else            {                newhead->_prev = tmp;                tmp->_next = newhead;                            newhead = tmp;                _head = newhead;                _head->_prev = NULL;            }                }    }    //打印    void PrintList()    {        ListNode* cur = _head;        while (cur)        {            cout << cur->_data << "->";            cur = cur->_next;        }        cout << "NULL" << endl;    }private:    ListNode* _head;    ListNode* _tail;};void Test(){    List s;    s.PushBack(1);    s.PushBack(2);    s.PushBack(3);    s.PushBack(4);    s.PushBack(5);    s.PrintList();    s.PopBack();    s.PrintList();    s.PushFront(0);    s.PrintList();    s.PopFront();    s.PrintList();    s.Insert(2, 10);    s.PrintList();    s.Reverse();    s.PrintList();}#endif //__LIST_H__

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