问题：
Problem K: Shape系列-4
Time Limit: 1 Sec
Memory Limit: 128 MB
Submit: 240
Solved: 205
[ Submit][ Status][ Web Board]
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
#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:"< return 0;
}
提示：不用提交全部程序，只提交补充部分。
Input
Output
Sample Output
RsubC area:2.86
代码：
#include
#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;
}
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,int s):Rectangle(c,w,h),Circle(c,r),sign(s){}
bool t()
{
if(sign==1)
return true;
else
return false;
}
double area()
{
if (t())
return Rectangle::area()-Circle::area();
else
return Rectangle::area()+Circle::area();
}
private:
int sign;
};
int main()
{
RsubC rc=RsubC(1,2,3,1,1);
cout<<"RsubC area:"<
运行结果：
学习心得：对bool型函数的使用还不熟练，希望这次以后能够记住怎么使用。
程序修改：在新增布尔类型的数据成员sign这个位置，可以写出如下代码：
class RsubC:public Rectangle,public Circle
{
public:
.......
double area()
{
if(sign);
return Rectangle::area()-Circle::area();
else
return Rectangle::area()+Circle::area();
private:
bool sign;
}；
