数据结构与算法（C语言版）__链表

数组的缺点：当插入数据时，后面的所有数据都要向后移位，删除数据时，后面的数据都要向前移位

所以出现链表，链表的插入和删除都比较快，链表不需要移位。

下面使用友元类和嵌套类实现链表

在VS2013中新建项目，在头文件中添加ThreeLetterList.h在源文件中添加main.cpp

//ThreeLetterList.h
#ifndef THREELETTERLIST_H
#define THREELETTERLIST_H

#include<iostream>

class ThreeLetterList{
private:
//嵌套类
class ThreeLetterNode{
public:
char data[3];
ThreeLetterNode * link;
};
ThreeLetterNode * first;
public:
void test();
void show();
};

void ThreeLetterList::test(){
ThreeLetterNode *f = new ThreeLetterNode();
f->data[0] = 'B';
f->data[1] = 'A';
f->data[2] = 'T';
f->link = 0;
first = f;

f = new ThreeLetterNode();
f->data[0] = 'C';
f->data[2] = 'T';
f->data[1] = 'A';
f->link = 0;
first->link = f;
}
void ThreeLetterList::show(){
std::cout << first->data[0] << first->data[1] << first->data[2] << " -> "
<< first->link->data[0] << first->link->data[1] << first->link->data[2] << std::endl;
}

#endif

//main.cpp
#include<iostream>
#include"ThreeLetterList.h"

using namespace std;

class List;

class Node{
friend class List;//使用友元类
private:
int data;//节点里的数据
Node* link;//指向下一个节点的指针
};

class List{
public:
void test();
void show();
private:
Node * first;
};

void List::show(){
cout << first->data << " -> "
<< first->link->data << " -> "
<< first->link->link->data << endl;
}
void List::test(){
Node *f = new Node();
f->data = 44;
f->link = 0;
first = f;

f = new Node();
f->data = 72;
f->link = 0;

first->link = f;

f = new Node();
f->data = 210;
f->link = 0;
first->link->link = f;
}

int main(){
List a;
a.test();//创建三个节点
a.show();

ThreeLetterList l;
l.test();
l.show();
cout << "OK" << endl;
system("pause");
return 0;
}

总结：链表是第二常用的数据结构，链表有单链表。但是这里没有写链表的删除，今后会重新实现完整的链表。