[YTU]_2918( Shape系列-4)

Description
小聪送给小亮和小华的形状他们都很喜欢,小亮和小华非要比一下他们两个的形状，来看看小聪更爱谁，请完成RsubC类。RsubC类中包括Rectangle类和Circle类的数据成员，新增布尔类型的数据成员sign（sign等于0时，新面积等于Rectangle+Circle，sign等于1时，新面积等于Rectangle-Circle），新定义了求面积的成员函数area()。但是小聪没有为RsubC类写构造函数和成员函数，请帮助小聪完成RsubC类。
小强写的文件头和Shape类
#include<iostream>
 #define PI 3.14
 using namespace std;
class Shape
 {
 public: 
  Shape();
  Shape(int c);
  int getcolor();
  double area();
 protected:
  int color;
 };
 Shape::Shape()
 {
  color=0;
 }
 Shape::Shape(int c)
 {
  color=c;
 }
 int Shape::getcolor()
 {
  return color;
 }
 double Shape::area()
 {
  return 10000;
 }
小聪写的Rectangle类
 class Rectangle:public Shape
 {
 public:
  Rectangle(int c,double w,double h);
  double getwidth();
  double getheight();
  double area();
  double price();
 protected:
  double height;
  double width;
 };
 Rectangle::Rectangle(int c,double w,double h):Shape(c)
 {
  width=w;
  height=h;
 }
 double Rectangle::getwidth()
 {
  return width;
 }
 double Rectangle::getheight()
 {
  return height;
 }
 double Rectangle::area()
 {
  return height*width;
 }
 double Rectangle::price()
 {
  return height*width*color;
 }
小聪写的Circle类
class Circle:public Shape
 {
 public:
  Circle(int c,double r);
  double getradius();
  double area();
  double price();
 protected:
  double radius;
 };
Circle::Circle(int c,double r):Shape(c)
 {
  radius=r;
 }
 double Circle::getradius()
 {
  return radius;
 }
double Circle::area()
 {
  return PI*radius*radius;
 }
 double Circle::price()
 {
  return PI*radius*radius*color;
 }
小聪的测试函数：
int main()
{
RsubC rc=RsubC(1,2,3,1,1);
 cout<<"RsubC area:"<<rc.area()<<endl;
 return 0;
}
提示：不用提交全部程序，只提交补充部分。
Input
无
Output
输出小聪测试的RsubC的面积。
Sample Output
RsubC area:2.86
#include<iostream>#define PI 3.14using namespace std;class Shape{public: Shape(); Shape(int c); int getcolor(); double area();protected: int color;};Shape::Shape(){ color=0;}Shape::Shape(int c){ color=c;}int Shape::getcolor(){ return color;}double
 Shape::area(){ return 10000;} class Rectangle:public Shape{public: Rectangle(int c,double w,double h); double getwidth(); double getheight(); double area(); double price();protected: double height; double width;};Rectangle::Rectangle(int c,double w,double
 h):Shape(c){ width=w; height=h;}double Rectangle::getwidth(){ return width;}double Rectangle::getheight(){ return height;}double Rectangle::area(){ return height*width;}double Rectangle::price(){ return height*width*color;} class Circle:public Shape{public:
 Circle(int c,double r); double getradius(); double area(); double price();protected: double radius;}; Circle::Circle(int c,double r):Shape(c){ radius=r;}double Circle::getradius(){ return radius;} double Circle::area(){ return PI*radius*radius;}double Circle::price(){
 return PI*radius*radius*color;}class RsubC:public Rectangle,public Circle{public: RsubC(int c,double w,double h,double r,bool s):Rectangle(c,w,h),Circle(c,r),sign(s){} float area();private: bool sign;};float RsubC::area(){ if(sign==1) return Rectangle::area()-Circle::area();
 if(sign==1) return Rectangle::area()+Circle::area();}int main(){ RsubC rc=RsubC(1,2,3,1,1);cout<<"RsubC area:"<<rc.area()<<endl;return 0; }