数据结构-双链表

// nodelist.h#ifndef NODELIST_H#define NODELIST_Htemplate<typename Type> class DoublyList;template<typename Type> class ListNode{private:    friend class DoublyList<Type>;    ListNode() : m_pprior(NULL),m_pnext(NULL){}    ListNode(const Type item, ListNode<Type>* prior = NULL, ListNode<Type>* next = NULL)        : m_data(item), m_pprior(prior), m_pnext(next){}    ~ListNode()    {        m_pprior = NULL;        m_pnext = NULL;    }public:    Type GetData();private:    Type m_data;    ListNode* m_pprior;    ListNode* m_pnext;};template<typename Type> Type ListNode<Type>::GetData(){    return this->m_data;}#endif // NODELIST_H

// doublelist.h#ifndef DOUBLELIST_H#define DOUBLELIST_H#include "nodelist.h"#include <iostream>template<typename Type> class DoublyList{public:    DoublyList() : head(new ListNode<Type>())    {        head->m_pprior = head;        head->m_pnext = head;    }    ~DoublyList()    {        MakeEmpty();        delete head;    }public:    void MakeEmpty();    int Length();    ListNode<Type>* Find(int n = 0);    ListNode<Type>* FindData(Type item);    bool Insert(Type item, int n = 0);    Type Remove(int n = 0);    Type Get(int n = 0);    void Print();private:    ListNode<Type> *head;};template<typename Type> void DoublyList<Type>::MakeEmpty(){    ListNode<Type> *pIterator = head->m_pnext, *pdel;    while(pIterator != head)    {        pdel = pIterator;        pIterator = pIterator->m_pnext;        delete pdel;    }    head->m_pnext = head;    head->m_pprior = head;}template<typename Type> int DoublyList<Type>::Length(){    ListNode<Type> *pprior = head->m_pprior, *pnext = head->m_pnext;    int count = 0;    while(1)    {        if(pprior->m_pnext == pnext) // pprior == head        {            break;        }        if(pprior == pnext && pprior != head)        {            count++;            break;        }        count += 2;        pprior = pprior->m_pprior;        pnext = pnext->m_pnext;    }    return count;}template<typename Type> ListNode<Type>* DoublyList<Type>::Find(int n){    if(n < 0)    {        std::cout << "The n is out of boundary" << std::endl;        return NULL;    }    ListNode<Type> *pcursor = head->m_pnext;    for( int i = 0; i < n; i++)    {        pcursor = pcursor->m_pnext;        if( pcursor == head)        {            std::cout << "The n is out of boundary" << std::endl;            return NULL;        }    }    return pcursor;}template<typename Type> ListNode<Type>* DoublyList<Type>::FindData(Type item){    ListNode<Type> *pcursorP = head->m_pprior;    ListNode<Type> *pcursorN = head->m_pnext;    while(pcursorP->m_pnext != pcursorN && pcursorP != pcursorN)    {        if(pcursorP->m_data == item)        {            return pcursorP;        }        if(pcursorN->m_data == item)        {            return pcursorN;        }        pcursorP = pcursorP->m_pprior;        pcursorN = pcursorN->m_pnext;    }        std::cout << "can't find the item you want to find" << std::endl;        return NULL;}template<typename Type> bool DoublyList<Type>::Insert(Type item, int n){    if(n<0)    {        std::cout << "The n is out of boundary" << std::endl;        return 0;    }    ListNode<Type> *newnode = new ListNode<Type>(item), *pcursor = head;    if(newnode == NULL)    {        std::cout << __FUNCTION__ << " error " << std::endl;        exit(1);    }    for(int i = 0; i < n; i++)    {        pcursor = pcursor->m_pnext;        if(pcursor == head)        {            std::cout << "The n is out of boundary" << std::endl;            exit(1);        }    }    newnode->m_pnext = pcursor->m_pnext;    newnode->m_pprior = pcursor;    newnode->m_pnext->m_pprior = newnode;    pcursor->m_pnext = newnode;    return 1;}template<typename Type> Type DoublyList<Type>::Remove(int n){    if(n<0)    {        std::cout << "The n is out of boundary" << std::endl;        exit(1);    }    ListNode<Type> *pcursor = head, *pdel = NULL;    for(int i = 0; i < n; i++)    {        pcursor = pcursor->m_pnext;        if(pcursor == head)        {            std::cout << "The n is out of boundary" << std::endl;            exit(1);        }    }    pdel = pcursor;    pcursor->m_pprior->m_pnext = pdel->m_pnext;    pcursor->m_pnext->m_pprior = pdel->m_pprior;    Type tmp = pdel->m_data;    delete pdel;    return tmp;}template<typename Type> Type DoublyList<Type>::Get(int n){    if(n<0)    {        std::cout << "The n is out of boundary" << std::endl;        exit(1);    }    ListNode<Type> *pcursor = head;    for(int i = 0; i < n; i++)    {        pcursor = pcursor->m_pnext;        if(pcursor == head)        {            std::cout << "The n is out of boundary" << std::endl;            exit(1);        }    }    return pcursor->m_data;}template<typename Type> void DoublyList<Type>::Print(){    ListNode<Type> *pcursor = head;    std::cout << "head";    while(pcursor->m_pnext != head)    {        std::cout << "--->" << pcursor->m_pnext->m_data;        pcursor = pcursor->m_pnext;    }    std::cout << "--->over" << std::endl << std::endl << std::endl;}#endif // DOUBLELIST_H

// main.cpp#include <iostream>#include "doublelist.h"using namespace std;int main(int argc, char *argv[]){    DoublyList<int> list;    for(int i = 0; i < 20; i++)    {        list.Insert(i*3, i);    }    cout << "the length of the list is " << list.Length() << endl;    list.Print();    for(int i = 0; i < 5; i++)    {        list.Insert(3, i*3);    }    cout << "the length of the list is " << list.Length() << endl;    list.Print();    list.Remove(5);    cout << "the length of the list is " << list.Length() << endl;    list.Print();    cout << list.FindData(54)->GetData() << endl;    cout << "the third element is " << list.Get(3) << endl;    list.MakeEmpty();    cout << "the length of the list is " << list.Length() << endl;    list.Print();    return 0;}