STL之双向链表及其迭代器简单实现

来源：互联网发布：复杂网络传播模型编辑：程序博客网时间：2024/05/21 08:14

最近在看STL，试着写一个自己的链表模板，与STL相比没有使用空间配置器，方法也只实现了几个简单的插入删除元素。但是理清了容器、迭代器之间的关系。代码及测试用例如下。

list_test.h文件# ifndef LIST_TEST# define LIST_TEST#include<iostream>template <typename T>class listnode{    public:    listnode<T>* prev;    listnode<T>* next;    T data;};template <typename T>class list_iterator{    typedef listnode<T>* link_type;    public:        listnode<T>* node;        list_iterator()        {            node = NULL;        }        list_iterator(link_type n)        {            node = n;        }        bool operator==(const list_iterator& x) const        {            return node == x.node;        }        bool operator!=(const list_iterator& x)const        {            return node != x.node;        }        T operator*() const        {            return node->data;        }        list_iterator operator++()        {            node = node->next;            return *this;        }        list_iterator operator++(int)        {            list_iterator tmp=*this;            ++*this;            return tmp;        }        list_iterator operator--()        {            node = node->prev;            return *this;        }        list_iterator operator--(int)        {            list_iterator tmp = *this;            --*this;            return tmp;        }};template <typename T>class list_test{    typedef listnode<T> list_node;    typedef listnode<T>* link_type;    typedef list_iterator<T> iterator;    public:        link_type head;        link_type get_node()        {            return new list_node();        }        list_test()        {            head = get_node();            head->next = head;            head->prev = head;        }        list_test(const list_test& source)        {            this->head = get_node();           //此处三行不可以直接调用构造函数            this->head->next = head;            this->head->prev = head;            link_type tmp = source.head->prev;            while (tmp != source.head)            {                this->put_front(tmp->data);                tmp = tmp->prev;            }        }        ~list_test()        {            link_type tmp1 = head;            link_type tmp2 = head->prev;            while (tmp2 != head)            {                tmp1 = tmp2->prev;                delete tmp2;                tmp2 = tmp1;            }            delete head;            head = NULL;        }        iterator insert(iterator pos,const T value)        {            link_type temp = get_node();            temp->data = value;            temp->next = pos.node;            temp->prev = pos.node->prev;            pos.node->prev->next = temp;            pos.node->prev = temp;            return temp;        }        iterator put_back(const T value)        {            iterator temp = this->insert(head, value);            return temp;        }        iterator put_front(const T value)        {            iterator temp = this->insert(head->next, value);            return temp;        }        iterator begin()        {            return head->next;        }        iterator end()        {            return head;        }        iterator erase(iterator position)        {            link_type next_node = link_type(position.node->next);            link_type prev_node = link_type(position.node->prev);            prev_node->next = next_node;            next_node->prev = prev_node;            delete position.node;            return iterator(next_node);        }};# endif

#include <string.h>#include <stdlib.h>#include <stdio.h>#include "list_test.h"using namespace std;int main(int argv, char** argc){    list_test < int > test ;    for (int n = 0; n < 5; ++n)    {        test.put_front(n);                       //方法测试    }    for (auto i = test.begin(); i != test.end();i++)    {        cout << *i << " ";    }    cout << endl;    list_test < int > *test1 = new list_test < int >();                for (int n = 0; n < 5; ++n)    {        test1->put_front(n);    }    for (auto i = test1->begin(); i != test1->end(); i++)    {        cout << *i << " ";    }    cout << endl;    delete test1;                      //析构函数测试    list_test < int > test2(test);     //拷贝复制函数测试    test2.erase(++test2.begin());      //方法测试    test2.put_back(-1);                //方法测试    test2.put_front(5);                //方法测试    for (auto i = test2.begin(); i != test2.end(); i++)    {        cout << *i << " ";    }    cout << endl;}

测试结果如下图这里写图片描述

另外给出析构函数的测试截图
执行析构函数前，test1所指链表的head指向0x00319288内存单元
这里写图片描述
执行析构指令后head被复位为0xfeee，但test1存在与栈上，仍然存在，此时test1便成为野指针。

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