C/code/几何图形的继承和派生（有输入）.cpp

#include <iostream>
#include <cmath>
#include <iomanip>
#define pi 3.14

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

class Circle : public Shape {
private:
    double radius;
public:
    Circle(double r) : radius(r) {}
    double GetArea() const override {
        return pi * radius * radius;
    }
};

class Rectangle : public Shape {
private:
    double length;
    double width;
public:
    Rectangle(double l, double w) : length(l), width(w) {}
    double GetArea() const override {
        return length * width;
    }
};

class Square : public Rectangle {
public:
    Square(double side) : Rectangle(side, side) {}
};

int main() {
    double radius;
    std::cin >> radius;
    Circle* circle = new Circle(radius);
    std::cout << "The area of the Cirele is:" << circle->GetArea() << std::endl;
    delete circle;


    double length, width;
    std::cin >> length >> width;
    Rectangle* rectangle = new Rectangle(length, width);
    std::cout << "The area of the Recanale is:" << rectangle->GetArea() << std::endl;
    delete rectangle;


    double side;
    std::cin >> side;
    Square* square = new Square(side);
    std::cout << "The area of the Recanale is:" << square->GetArea() << std::endl;
    delete square;

    return 0;
}