链式线性表C++ 实现

1.头文件

#ifndef _LINK_LIST_H
#define _LINK_LIST_H


template <typename T>
struct LinkListNode
{
	T t;//节点包含的数据
	LinkListNode<T> *next;//指向下一个节点的指针（正好和节点的数据类型一样）
};

//采用模板类，实现链式线性表
template<typename T>
class CLinkList
{
public:
	CLinkList();
	~CLinkList();
	
	//插入一个节点
	int insertNode(T &t,int nPos);

	//获取一个节点
	T * getNode(int nPos);

	//删除一个节点
	T * delNode(int nPos);

	//获取链式线性表的长度
	int getLen();

	//清空线性表
	void Clear();

//如果想被继承，关键字可以改成protect
private:
	int m_nLen;//线性表的长度
	LinkListNode<T> *m_pHead;//头结点
};



#endif //_LINK_LIST_H

2.源文件

#include <iostream>
#include "LinkList.h"
#include "vld.h"

using namespace std;

template<typename T>
CLinkList<T>::CLinkList()
{
	m_pHead=new LinkListNode<T>;
	memset(m_pHead,0,sizeof(LinkListNode<T>));
	m_pHead->next=NULL;
	m_nLen=0;
}

template<typename T>
CLinkList<T>::~CLinkList()
{
	if (m_pHead!=NULL)
	{
		delete m_pHead;
		m_pHead=NULL;
	}
	m_nLen=0;
}

template<typename T>
int CLinkList<T>::insertNode(T &t,int nPos)
{
	if (nPos<0)
	{
		cout<<"insertNode parameter is error";
		return -1;
	}
	LinkListNode<T> *pCurrent=NULL;
	pCurrent=m_pHead;//首先赋值给头节点
	for (int i=0;i<nPos;i++)
	{
		pCurrent=pCurrent->next;
	}

	//把上层应用的t节点缓存到容器中
	LinkListNode<T> *pNode=new LinkListNode<T>;
	memset(pNode,0,sizeof(LinkListNode<T>));
	pNode->t=t;
	pNode->next=NULL;

	//分两步实现加入节点
	pNode->next=pCurrent->next;
	pCurrent->next=pNode;

	m_nLen++;

	return 0;
}

template<typename T>
T* CLinkList<T>::getNode(int nPos)
{
	if (nPos<0||nPos>m_nLen)
	{
		cout<<"getNode() paramerter is error"<<endl;
		return NULL;
	}

	LinkListNode<T> *pCurrent=NULL;
	pCurrent=m_pHead;//首先赋值给头节点
	for (int i=0;i<nPos;i++)
	{
		pCurrent=pCurrent->next;
	}

	//T t=pCurrent->next->t;//这是个临时变量，当返回值是，临时变量被析构掉，出现乱码
	//return &t;
	T *pT=new T;
	memset(pT,0,sizeof(T));
	*pT=pCurrent->next->t;
	cout<<pT<<endl;

	return pT;
}

template<typename T>
int CLinkList<T>::getLen()
{
	return m_nLen;
}

template<typename T>
T* CLinkList<T>::delNode(int nPos)
{
	if (nPos<0||nPos>m_nLen)
	{
		cout<<"delNode() paramerter is error"<<endl;
		return NULL;
	}
	LinkListNode<T> *pCurrent=NULL;
	pCurrent=m_pHead;//首先将当前节点赋给头节点
	for (int i=0;i<nPos;i++)
	{
		pCurrent=pCurrent->next;
	}

	LinkListNode<T> *rect=NULL;
	rect=pCurrent->next;
	T *pT=new T;
	memset(pT,0,sizeof(T));
	if (rect!=NULL)
	{
		*pT=rect->t;
		//删除操作
		pCurrent->next = rect->next; 
		m_nLen--;
		delete rect;//释放内存，因为插入节点的时候是new
	}

	return pT;
}

template<typename T>
void CLinkList<T>::Clear()
{
	//把旧的结点 del掉
	LinkListNode<T> *tmp = NULL;

	while (m_pHead)
	{
		tmp = m_pHead->next;
		delete m_pHead;
		m_pHead = tmp;
	}

	//重新创建
	m_pHead = new LinkListNode<T>;
	m_nLen = 0;
}

3.测试程序

#include <iostream>
#include "LinkList.hpp"
#include <string>

using namespace std;

typedef struct _Teacher
{
	char sName[64];
	int nAge;
}Teacher;

int main()
{
	Teacher t1,t2,t3;
	memset(&t1,0,sizeof(Teacher));
	memset(&t2,0,sizeof(Teacher));
	memset(&t3,0,sizeof(Teacher));
	t1.nAge=10;
	strcpy(t1.sName,"小李");

	t2.nAge=11;
	strcpy(t2.sName,"小张");

	t3.nAge=12;
	strcpy(t3.sName,"小刘");

	CLinkList<Teacher> list;

	list.insertNode(t1,0);
	list.insertNode(t2,1);
	list.insertNode(t3,2);

	int nLen=list.getLen();
	cout<<"共"<<nLen<<"节点"<<endl;

	for (int i=0;i<nLen;i++)
	{
		Teacher *pTeacher=list.getNode(i);
		if (pTeacher!=NULL)
		{
			cout<<pTeacher->sName<<"  "<<pTeacher->nAge<<endl;
			delete pTeacher;
			pTeacher=NULL;
		}
		else
		{
			cout<<"获取节点指针为空"<<endl;
		}
	}

	while (list.getLen()>0)
	{
		Teacher *pTeacher=list.delNode(0);
		if (pTeacher!=NULL)
		{
			cout<<"删除节点:"<<pTeacher->sName<<"  "<<pTeacher->nAge<<endl;
			delete pTeacher;
		}
		
	}

	 nLen=list.getLen();
	cout<<"共"<<nLen<<"节点"<<endl;

	for (int i=0;i<nLen;i++)
	{
		Teacher *pTeacher=list.getNode(i);
		if (pTeacher!=NULL)
		{
			cout<<pTeacher->sName<<"  "<<pTeacher->nAge<<endl;
		}
		else
		{
			cout<<"获取节点指针为空"<<endl;
		}
	}

   return 0;
}