优化这段代码：#include <iostream> #include <cmath> using namespace std; class Shape{ public: virtual double GetArea()=0; virtual double GetPerimeter()=0; }; class Circle:public Shape{ double r1; public: Circle(double _r):r1(_r){} double GetArea(){ return 3.14*r1*r1; } double GetPerimeter(){ return 2*3.14*r1; } }; class Outside:public Shape{ double r2; public: Outside(double _r):r2(_r){} double GetArea(){ return 4*r2*r2; } double GetPerimeter(){ return 8*r2; } }; class Inside:public Shape{ double r3; public: Inside(double _r):r3(_r){} double d=sqrt(2*r3*r3); double GetArea(){ return d*d; } double GetPerimeter(){ return 4*d; } }; int main(){ Shape *C=new Circle(2.0); cout<<C->GetArea()<<" "<<C->GetPerimeter<<endl; Shape *O=new Outside(2.0); cout<<O->GetArea()<<" "<<O->GetPerimeter<<endl; Shape *I=new Inside(2.0); cout<<I->GetArea()<<" "<<I->GetPerimeter<<endl; delete C; delete O; delete I; return 0; }

以下是优化后的代码：

#include <iostream>
#include <cmath>

using namespace std;

class Shape{
public:
    virtual double GetArea() const = 0;
    virtual double GetPerimeter() const = 0;
};

class Circle : public Shape{
private:
    double r;
public:
    Circle(double _r) : r(_r){}
    double GetArea() const override {
        return 3.14 * r * r;
    }
    double GetPerimeter() const override {
        return 2 * 3.14 * r;
    }
};

class Outside : public Shape{
private:
    double r;
public:
    Outside(double _r) : r(_r){}
    double GetArea() const override {
        return 4 * r * r;
    }
    double GetPerimeter() const override {
        return 8 * r;
    }
};

class Inside : public Shape{
private:
    double r;
public:
    Inside(double _r) : r(_r){}
    double GetArea() const override {
        double d = sqrt(2) * r;
        return d * d;
    }
    double GetPerimeter() const override {
        return 4 * sqrt(2) * r;
    }
};

int main(){
    Shape *C = new Circle(2.0);
    cout << C->GetArea() << " " << C->GetPerimeter() << endl;

    Shape *O = new Outside(2.0);
    cout << O->GetArea() << " " << O->GetPerimeter() << endl;

    Shape *I = new Inside(2.0);
    cout << I->GetArea() << " " << I->GetPerimeter() << endl;

    delete C;
    delete O;
    delete I;

    return 0;
}

优化内容：

1. 将 Shape 类中的纯虚函数的返回类型改为 const，以避免意外修改数据。

2. 将 Circle、Outside、Inside 类中的成员变量名更改为更有意义的名字，方便代码阅读。

3. 将 Inside 类中的计算对角线长度的语句放入 GetArea 函数内，避免在类定义中进行计算。

4. 将 Inside 类中的计算周长的语句放入 GetPerimeter 函数内，避免在类定义中进行计算。