声明类Shape以及它的3个派生类：Circle、Square、Rectangle，输入半径、边长、长和宽，用虚函数分别计算几种图形的面积、周长，编写程序，建立基类指针数组，每个指针均指向一个派生类对象，利用基类指针 遍历元素对象，求取所有图形面积之和。请绘制UML类图。、

好的，以下是类的UML类图：

+----------------+
|      Shape     |
+----------------+
|                |
|  - radius: int |
|  - side: int   |
|  - length: int |
|  - width: int  |
|                |
+----------------+
|                |
|+ calcArea():    |
|+ calcPerimeter: |
|                |
+----------------+

        /         |        \
+------------+ +-----------+ +--------------+
|   Circle   | |   Square  | |  Rectangle   |
+------------+ +-----------+ +--------------+
|            | |           | |              |
|+ calcArea()| |+ calcArea()| |+ calcArea()  |
|+ calcPeri()| |+ calcPeri()| |+ calcPeri()  |
|            | |           | |              |
+------------+ +-----------+ +--------------+

下面是这些类的代码实现：

#include <iostream>
#include <cmath>
using namespace std;

class Shape {
protected:
    int radius;
    int side;
    int length;
    int width;
public:
    Shape() {}
    virtual ~Shape() {}
    virtual double calcArea() = 0;
    virtual double calcPerimeter() = 0;
};

class Circle : public Shape {
public:
    Circle(int r) : radius(r) {}
    virtual ~Circle() {}
    virtual double calcArea() override {
        return M_PI * radius * radius;
    }
    virtual double calcPerimeter() override {
        return 2 * M_PI * radius;
    }
};

class Square : public Shape {
public:
    Square(int s) : side(s) {}
    virtual ~Square() {}
    virtual double calcArea() override {
        return side * side;
    }
    virtual double calcPerimeter() override {
        return 4 * side;
    }
};

class Rectangle : public Shape {
public:
    Rectangle(int l, int w) : length(l), width(w) {}
    virtual ~Rectangle() {}
    virtual double calcArea() override {
        return length * width;
    }
    virtual double calcPerimeter() override {
        return 2 * (length + width);
    }
};

int main() {
    Shape* shapes[] = {
        new Circle(3),
        new Rectangle(4, 5),
        new Square(2),
        new Circle(4),
        new Rectangle(2, 6)
    };

    double total_area = 0.0;
    for (int i = 0; i < 5; i++) {
        total_area += shapes[i]->calcArea();
    }

    cout << "Total area: " << total_area << endl;

    for (int i = 0; i < 5; i++) {
        delete shapes[i];
    }

    return 0;
}