数据结构_静态链表

C++实现静态链表

注意理解headp,searchp,followp,newnodep的角色与功能.

特别是searchp,followp.

// 静态链表.cpp: 定义控制台应用程序的入口点。
//

#include "stdafx.h"
#include<iostream>
using namespace std;

class node
{
public:
	int data;
	node *next;
};

class link
{
private:
	node * headp;
protected:
	int count;
public:
	link();
	~link();
	void create(int *data, int size);			//初始化链表
	void clearlink();							//清空链表
	void display();								//打印链表元素
	int getlen();								//获取链表实际长度
	void insert(int position, int item);		//指定位置插入元素
	void remove(int position);					//指定位置删除元素
	void update(int position, int item);		//指定位置更新元素
	int getonedata(int position);				//指定位置获取元素
};

link::link()
{
	count = 0;
	headp = new node;
	headp->next = NULL;
}

link::~link()
{
	clearlink();
	delete headp;
	count = 0;
}

void link::create(int * data, int size)
{
	node *searchp = headp, *newnodep;
	for (int i = 0; i < size; i++)
	{
		newnodep = new node;
		newnodep->data = data[i];
		newnodep->next = NULL;
		searchp->next = newnodep;
		searchp = newnodep;
		count++;
	}
	searchp->next = NULL;						//通过searchp实现循环的上下连接
}

void link::clearlink()
{
	node *searchp = headp, *followp = headp;
	while (searchp!=NULL) 
	{
		followp = searchp;
		searchp = searchp->next;
		delete followp;							//删除关键语句
	}
	headp->next = NULL;
	count = 0;
}

void link::display()
{
	node *searchp = headp->next;
	while (searchp != NULL)
	{
		cout << searchp->data << " ";
		searchp = searchp->next;
	}
	cout << endl;
}

int link::getlen()
{
	return count;
}

void link::insert(int position, int item)
{
	node *searchp = headp->next, *followp = headp, *newnodep;
	for (int i = 1; i < position&&searchp != NULL; i++)
	{
		followp = searchp;
		searchp = searchp->next;
	}
	newnodep = new node;	
	newnodep->data = item;							//注意语句顺序
	newnodep->next = searchp;	
	followp->next = newnodep;
	count++;										//理解searchp,followp的思想
}

void link::remove(int position)
{
	node *searchp = headp->next, *followp = headp;
	for (int i = 1; i < position&&searchp != NULL; i++)
	{
		followp = searchp;
		searchp = searchp->next;
	}
	followp->next = searchp->next;
	count--;										//理解searchp,followp的思想
	delete searchp;			
}

void link::update(int position, int item)
{
	node *searchp = headp->next;
	for (int i = 1; i < position&&searchp != NULL; i++)
	{
		searchp = searchp->next;
	}
	searchp->data = item;							//理解searchp的思想
}

int link::getonedata(int position)
{
	node *searchp = headp->next;
	for (int i = 1; i < position&&searchp != NULL; i++)
		searchp = searchp->next;
	return searchp->data;							//理解searchp的思想
}
int main()
{
	int data[8] = { 1,2,3,4,5,6,7,8 };
	int size = sizeof(data) / sizeof(data[0]);
	link l = link();
	l.create(data, 8);
	l.display();
	l.insert(2, 10);
	l.display();
	l.remove(2);
	l.display();
	l.update(2, 15);
	l.display();
	cout << "当前长度为:" << l.getlen() << endl;
	cout << "第二个元素为:" << l.getonedata(2) << endl;
	l.clearlink();
	cout << "当前长度为:" << l.getlen() << endl;
	system("pause");
	return 0;
}