异质链表（C++）

请编写程序创建一异质链表。该链表内有四种节点类型。
第一种：每节点能存储一最多20个字符的字符串；
第二种：每节点能存储三个整数；
第三种：每节点能存储两个浮点数；
第四种：每节点能存储两个整数和一个浮点数。
要求：主函数以4-1-4-1-2-3-3-4-2-3-2-1-4的顺序创建链表并遍历输出。

#include<iostream.h>
#include<string.h>
#include<conio.h>
class Base
{
public:
virtual void show_data() = 0 ;
};
class Node1 : public Base
{
private:
char data1[21];
public:
void set(const char *d1)
{
strcpy(data1,d1);
}
virtual void show_data()
{
cout<<endl<<" Node 1 Include : "<<data1<<endl;
}
};
class Node2 : public Base
{
private:
int data2,data3,data4;
public:
void set(int d2,int d3,int d4)
{
data2 = d2 ;
data3 = d3 ;
data4 = d4 ;
}
virtual void show_data()
{
cout<<endl<<" Node 2 Include : ";
cout<<data2<<" , "<<data3<<" , "<<data4<<endl;
}
};
class Node3 : public Base
{
private:
float data5,data6;
public:
void set(float d5,float d6)
{
data5 = d5 ;
data6 = d6 ;
}
virtual void show_data()
{
cout<<endl<<" Node 3 Include : ";
cout<<data5<<" , "<<data6<<endl;
}
};
class Node4 : public Base
{
private:
int data7,data8;
float data9;
public:
void set(int d7,int d8,float d9)
{
data7 = d7 ;
data8 = d8 ;
data9 = d9 ;
}
virtual void show_data()
{
cout<<endl<<" Node 4 Include : ";
cout<<data7<<" , "<<data8<<" , "<<data9<<endl;
}
};
void main(void)
{
clrscr();
Base *pBase = NULL;
Node1 *pNode1 = new Node1();
Node2 *pNode2 = new Node2();
Node3 *pNode3 = new Node3();
Node4 *pNode4 = new Node4();
pNode4 -> set(12,23,12.3);
pBase = pNode4;
pBase -> show_data();
pNode1 -> set("abcdefg");
pBase = pNode1;
pBase -> show_data();
pNode4 -> set(45,56,45.5);
pBase = pNode4;
pBase -> show_data();
pNode1 -> set("hijklmn");
pBase = pNode1;
pBase -> show_data();
pNode2 -> set(10,20,30);
pBase = pNode2;
pBase -> show_data();
pNode3 -> set(22.2,33.3);
pBase = pNode3;
pBase -> show_data();
pNode3 -> set(44.4,55.5);
pBase = pNode3;
pBase -> show_data();
pNode4 -> set(78,89,78.9);
pBase = pNode4;
pBase -> show_data();
pNode2 -> set(40,50,60);
pBase = pNode2;
pBase -> show_data();
pNode3 -> set(77.7,88.8);
pBase = pNode3;
pBase -> show_data();
pNode2 -> set(70,80,90);
pBase = pNode2;
pBase -> show_data();
pNode1 -> set("opqrstuvwxyz");
pBase = pNode1;
pBase -> show_data();
pNode4 -> set(123,456,123.456);
pBase = pNode4;
pBase -> show_data();
}