C8-2 圆的周长和面积 (100/100 分数)

题目描述

求圆的周长和面积，已知圆类从shape抽象类继承。

要求使用c++ class编写程序。可以创建如下class

#include <iostream>
using namespace std;

const double pi = 3.14;

class Shape{
public:
    Shape(){}
    ~Shape(){}
    virtual double getArea() = 0;
    virtual double getPerim() = 0;
};

class Circle: public Shape{
public:
    Circle(double rad):radius(rad){}
    ~Circle(){}
    
    /*补充这两个函数*/
    double getArea();
    double getPerim();
private:
    double radius;
};

int main() {
    double radius;
    cin >> radius;
    Circle c(radius);
    cout << c.getArea() << " " << c.getPerim() << endl;
}

输入描述

输入圆的半径

输出描述

输出圆的周长和面积

样例输入

10

样例输出

314 62.8

#include <iostream>
using namespace std;

const double pi = 3.14;

class Shape{
public:
    Shape(){}
    ~Shape(){}
    virtual double getArea() = 0;
    virtual double getPerim() = 0;
};

class Circle: public Shape{
public:
    Circle(double rad):radius(rad){}
    ~Circle(){}
    
    /*补充这两个函数*/
    double getArea();
    double getPerim();
private:
    double radius;
};

double Circle::getArea(){
    return (3.14*radius*radius);
}

double Circle::getPerim(){
    return (2*3.14*radius);
}

int main() {
    double radius;
    cin >> radius;
    Circle c(radius);
    cout << c.getArea() << " " << c.getPerim() << endl;
}