C++模板实现单链表

          单链表是一种链式存取的数据结构，用一组地址任意的存储单元存放线性表中的数据元素。表中的数据是以节点来表示的，每个结点的构成:元素(数据元素的映象) + 指针(指示后继元素存储位置)，元素就是存储数据的存储单元，指针就是连接每个结点的地址数据。以"结点的序列"表示线性表称作线性链表(单链表)

单链表是链式存取的结构，为找第 i 个数据元素，必须先找到第 i-1 个数据元素。

       了解了单链表结构，我们来用模板实现一个简单的单链表：

//ListNode.h

template<typename Type> class SingleList;template<typename Type> class ListNode{private:friend typename SingleList<Type>;ListNode():m_pnext(NULL){}ListNode(const Type item,ListNode<Type> *next=NULL):m_data(item),m_pnext(next){}~ListNode(){m_pnext=NULL;}public:Type GetData();friend ostream& operator<< <Type>(ostream& ,ListNode<Type>&);private:Type m_data;ListNode *m_pnext;};template<typename Type> Type ListNode<Type>::GetData(){return this->m_data;}template<typename Type> ostream& operator<<(ostream& os,ListNode<Type>& out){os<<out.m_data;return os;}

SingleList.h

#include "ListNode.h"template<typename Type> class SingleList{public:SingleList():head(new ListNode<Type>()){}~SingleList(){MakeEmpty();delete head;}public:void MakeEmpty();                       //make the list emptyint Length();                           //get the lengthListNode<Type> *Find(Type value,int n); //find thd nth data which is equal to valueListNode<Type> *Find(int n);            //find the nth databool Insert(Type item,int n=0);         //insert the data in the nth positionType Remove(int n=0);                   //remove the nth databool RemoveAll(Type item);              //remove all the data which is equal to itemType Get(int n);                        //get the nth datavoid Print();                           //print the listprivate:ListNode<Type> *head;};template<typename Type> void SingleList<Type>::MakeEmpty(){ListNode<Type> *pdel;while(head->m_pnext!=NULL){pdel=head->m_pnext;head->m_pnext=pdel->m_pnext;delete pdel;}}template<typename Type> int SingleList<Type>::Length(){ListNode<Type> *pmove=head->m_pnext;int count=0;while(pmove!=NULL){pmove=pmove->m_pnext;count++;}return count;}template<typename Type> ListNode<Type>* SingleList<Type>::Find(int n){if(n<0){cout<<"The n is out of boundary"<<endl;return NULL;}ListNode<Type> *pmove=head->m_pnext;for(int i=0;i<n&&pmove;i++){pmove=pmove->m_pnext;}if(pmove==NULL){cout<<"The n is out of boundary"<<endl;return NULL;}return pmove;}template<typename Type> ListNode<Type>* SingleList<Type>::Find(Type value,int n){if(n<1){cout<<"The n is illegal"<<endl;return NULL;}ListNode<Type> *pmove=head;int count=0;while(count!=n&&pmove){pmove=pmove->m_pnext;if(pmove->m_data==value){count++;}}if(pmove==NULL){cout<<"can't find the element"<<endl;return NULL;}return pmove;}template<typename Type> bool SingleList<Type>::Insert(Type item, int n){if(n<0){cout<<"The n is illegal"<<endl;return 0;}ListNode<Type> *pmove=head;ListNode<Type> *pnode=new ListNode<Type>(item);if(pnode==NULL){cout<<"Application error!"<<endl;return 0;}for(int i=0;i<n&&pmove;i++){pmove=pmove->m_pnext;}if(pmove==NULL){cout<<"the n is illegal"<<endl;return 0;}pnode->m_pnext=pmove->m_pnext;pmove->m_pnext=pnode;return 1;}template<typename Type> bool SingleList<Type>::RemoveAll(Type item){ListNode<Type> *pmove=head;ListNode<Type> *pdel=head->m_pnext;while(pdel!=NULL){if(pdel->m_data==item){pmove->m_pnext=pdel->m_pnext;delete pdel;pdel=pmove->m_pnext;continue;}pmove=pmove->m_pnext;pdel=pdel->m_pnext;}return 1;}template<typename Type> Type SingleList<Type>::Remove(int n){if(n<0){cout<<"can't find the element"<<endl;exit(1);}ListNode<Type> *pmove=head,*pdel;for(int i=0;i<n&&pmove->m_pnext;i++){pmove=pmove->m_pnext;}if(pmove->m_pnext==NULL){cout<<"can't find the element"<<endl;exit(1);}pdel=pmove->m_pnext;pmove->m_pnext=pdel->m_pnext;Type temp=pdel->m_data;delete pdel;return temp;}template<typename Type> Type SingleList<Type>::Get(int n){if(n<0){cout<<"The n is out of boundary"<<endl;exit(1);}ListNode<Type> *pmove=head->m_pnext;for(int i=0;i<n;i++){pmove=pmove->m_pnext;if(NULL==pmove){cout<<"The n is out of boundary"<<endl;exit(1);}}return pmove->m_data;}template<typename Type> void SingleList<Type>::Print(){ListNode<Type> *pmove=head->m_pnext;cout<<"head";while(pmove){cout<<"--->"<<pmove->m_data;pmove=pmove->m_pnext;}cout<<"--->over"<<endl<<endl<<endl;}

Main.cpp

#include <iostream>using namespace std;#include "SingleList.h"int main(){SingleList<int> list;for(int i=0;i<20;i++){list.Insert(i*3,i);}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();list.RemoveAll(3);cout<<"the Length of the list is "<<list.Length()<<endl;list.Print();cout<<"The third element is "<<list.Get(3)<<endl;cout<<*list.Find(18,1)<<endl;list.Find(100);list.MakeEmpty();cout<<"the Length of the list is "<<list.Length()<<endl;list.Print();return 0;}