Question

c++作业求第一题

c++作业求第一题用c++编写，谢谢

Answer 1

供参考因为

Answer 2

//类内实现
#include<iostream>

using namespace std;

class Circle
{
private:
double radius;
public:
Circle() { radius=0; }
Circle(double r) { radius=r; }
double GetRadius() { return radius; }
void setRadius(int r) { radius=r; }
double GetDiameter() { return 2*radius; }
double GetPerimeter() { return 6.28*radius; }
double GetArea() { return 3.14*radius*radius; }
};

int main()
{
Circle c;
int r;

cout<<"请输入圆的半径：";
cin>>r;
c.setRadius(r);
cout<<"半径为"<<c.GetRadius();
cout<<"的圆的直径为："<<c.GetDiameter();
cout<<"，周长为："<<c.GetPerimeter();
cout<<"，面积为："<<c.GetArea()<<endl;
return 0;
}
//类外实现
#include<iostream>

using namespace std;

class Circle
{
private:
double radius;
public:
Circle();
Circle(double r);
double GetRadius();
void setRadius(int r);
double GetDiameter();
double GetPerimeter();
double GetArea();
};
Circle::Circle() { radius=0; }
Circle::Circle(double r) { radius=r; }
double Circle::GetRadius() { return radius; }
void Circle::setRadius(int r) { radius=r; }
double Circle::GetDiameter() { return 2*radius; }
double Circle::GetPerimeter() { return 6.28*radius; }
double Circle::GetArea() { return 3.14*radius*radius; }

int main()
{
Circle c;
int r;

cout<<"请输入圆的半径：";
cin>>r;
c.setRadius(r);
cout<<"半径为"<<c.GetRadius();
cout<<"的圆的直径为："<<c.GetDiameter();
cout<<"，周长为："<<c.GetPerimeter();
cout<<"，面积为："<<c.GetArea()<<endl;
return 0;
}

Answer 3

唉，我是数学渣，复数不会