YTU 2920: Shape系列-7

2921: Shape系列-7

时间限制: 1 Sec  内存限制: 128 MB
提交: 156  解决: 129

题目描述

小强做的Shape类在本次的测试中出了点状况，发现原来是其中的area函数的问题，请大家根据题意，帮助小强完成改动后的Shape类。

小强写的各种类

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; 
}   
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 Triangle:  public Shape
{
public:
 Triangle(int c,double b,double h);
 double area();
protected:
 double base,height;
};
Triangle::Triangle(int c,double b,double h):Shape(c)
{
 base=b;height=h;
}
double Triangle::area()
{
 return 0.5*base*height;
}
int main() 
{ 
 Shape *pt[3];
 Rectangle rr(1,1,1);
 Circle cc(2,1);
 Triangle tt(2,1,3);
 pt[0]=&rr;
 pt[1]=&cc;
 pt[2]=&tt;
 cout<<"Rectangle area:"<<pt[0]->area()<<endl;
 cout<<"Circle area:"<<pt[1]->area()<<endl;
 cout<<"Triangle area:"<<pt[2]->area()<<endl;
return 0;  
}

提示：不用提交全部程序，只提交补充部分（包括头文件和π的定义）。

输入

无

输出

小强测试的各个类面积的数据

样例输出

Rectangle area:1
Circle area:3.14
Triangle area:1.5

im0qianqian_站在回忆的河边看着摇晃的渡船终年无声地摆渡,它们就这样安静地画下黄昏画下清晨......

#include<iostream>
using namespace std;
#define PI 3.14
class Shape
{
public:
    Shape(int c):color(c) {}
    virtual double area()=0;
    int color;
};
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 Triangle:  public Shape
{
public:
    Triangle(int c,double b,double h);
    double area();
protected:
    double base,height;
};
Triangle::Triangle(int c,double b,double h):Shape(c)
{
    base=b;
    height=h;
}
double Triangle::area()
{
    return 0.5*base*height;
}
int main()
{
    Shape *pt[3];
    Rectangle rr(1,1,1);
    Circle cc(2,1);
    Triangle tt(2,1,3);
    pt[0]=&rr;
    pt[1]=&cc;
    pt[2]=&tt;
    cout<<"Rectangle area:"<<pt[0]->area()<<endl;
    cout<<"Circle area:"<<pt[1]->area()<<endl;
    cout<<"Triangle area:"<<pt[2]->area()<<endl;
    return 0;
}