如果要设计一个图形系统，请你设计基本的图形元件(Point,Line,Rectangle,Triangle)的简单实现

如下，我基本已经给你写出来啦
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#include<iostream>
using namespace std;
class Graph
{
public:
virtual void count(){};
};
class Rectangle:public Graph
{
int n;
public:
Rectangle():n(0){}
void count()
{
n++;
}
void printn()
{
cout<<"Rectangle :"<<n<<endl;
}
};
class Circle:public Graph
{
int n;
public:
Circle():n(0){}
void count()
{
n++;
}
void printn()
{
cout<<"Circle :"<<n<<endl;
}
};
class Triangle:public Graph
{
int n;
public:
Triangle():n(0){}
void count()
{
n++;
}
void printn()
{
cout<<"Triangle :"<<n<<endl;
}
};
class Graphlist
{
public:
Graph &g;
Graphlist (Grap