class Base{private:int x;int y;public:Base();Base(int x,int y);virtual void draw();void move();};class Poit :virtual public Base{public:Poit();Poit(int x,int y);void draw();};class Line :virtual public Base{private:int a;int b;public:Line();Line(int a,int b,int x,int y);void draw();};class Circle :virtual public Base{private:int r;public:Circle();Circle(int x,int y,int r);void draw();};class Graphics :public Poit,public Line, public Circle{private:static int i;void (*pf[6])();public:void task(Poit *p); void task(Line *l);void task(Circle *c);void draw();};int Graphics::i=0;#include <iostream.h>#include "Graphics.h"Base::Base(){x=0;y=0;}Base::Base(int x,int y){this->x=x;this->y=y;}void Base::move(){cout<<"將畫筆移動到（"<<x<<","<<y<<"）,";}Poit::Poit():Base(0,0){}Poit::Poit(int x,int y):Base(x,y){}void Poit::draw(){Base::move();cout<<"畫一個(gè)點(diǎn)"<<endl;}Line::Line():Base(0,0){a=0;b=0;}Line::Line(int a,int b,int x,int y):Base(x,y){this->a=a;this->b=b;}void Line::draw(){Base::move();cout<<"畫一條到（"<<a<<","<<b<<"）的直線"<<endl;}Circle::Circle():Base(0,0){r=0;}Circle::Circle(int x,int y,int r):Base(x,y){this->r=r;}void Circle::draw(){Base::move();cout<<"畫一個(gè)半徑"<<r<<"的圓"<<endl;}void Graphics::draw(){int n;for(n=0;n<i;n++){cout<<"第"<<n<<"步:";(*pf[i])();}}void Graphics::task(Poit *p){pf[i]=p->draw;}void Graphics::task(Line *l){pf[i]=l->draw;}void Graphics::task(Circle *c){pf[i]=c->draw;}#include <iostream.h>#include "Graphics.h"int main(){Graphics g;g.task(new Poit(3,5));return 0;}