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Western Agricultural University C plus

2022-07-22 06:23:00 【numb and dying】

problem I: oop Internship -9. Abstract classes and operator overloading

Title Description

Define abstract classes and corresponding derived classes that represent shapes , And implement relevant operator overloading .

（1） Define abstract classes that represent shapes Shape：

Add public member function double Area(), Used to calculate shape area ; Defined as a pure virtual function ;

Add public member function void Show(), Used to display shape information , Defined as a pure virtual function ;

Define virtual destructors ;

Overload the comparison operator ：==、> and <, Used to compare the size relationship between the areas of two shapes , The return value type is bool, It can be defined as member function or friend function .

（2） From shape class Shape Derived rectangle class Rectangle：

add to double Type of protected data members ：rectWidth and rectHeight, Respectively represent the width and height of the rectangle ;

Define a constructor with parameters ;
Redefining public member functions Show, Print the width and height of the rectangle , The output format is “W: Width ; H: Height ; Area: area ”;
Redefining public member functions Area, Calculate rectangular area .

（3） From shape class Shape Derived ellipse class Ellipse：
add to double Type of protected data members ：rectWidth and rectHeight, Respectively represents the width and height of the rectangle circumscribed by the ellipse ;

Define a constructor with parameters ;
Redefining public member functions Show, Print the width and height of the rectangle surrounding the ellipse , The output format is “W: Width ; H: Height ; Area: area ”;
Redefining public member functions Area, Calculate the area of the ellipse .

stay main Function , First, create a corresponding size according to the input integer Shape Object pointer array , Then dynamically create objects of corresponding types according to the input object types and information , And associated to the object pointer array . The format of the input information is as follows ：

3 // Number of elements of the object pointer array

R 23 17    // object type 、 Shape width 、 Shape height ,R Represents a rectangular object
R 89 25    // object type 、 Shape width 、 Shape height ,R Represents a rectangular object
E 17 29    // object type 、 Shape width 、 Shape height ,E Represents an elliptical object

Then by calling Show The member function outputs the information of all objects .

Then output the information of shape objects with equal area （ Overloaded operators are required “==” To determine whether the area of the object is equal ）, The output format is as follows ：

Area of Shape[i] is equal to Shape[j]

Finally, all shape objects are sorted by area from large to small （ Overloaded operators are required “>” To judge the size relationship of the area of the object ）, And output the sorted object information .

Input

Number of objects

object type The width of the circumscribed rectangle of the object The height of the circumscribed rectangle of the object

Output

Object information before sorting

Object information with equal area

Sorted object information

Tips

#include <iostream>
using namespace std;

class Shape
{
    public:
        virtual double Area() = 0;
        virtual void Show() = 0;
        ~Shape() {}
        friend bool operator==(Shape& a, Shape& b);
        friend bool operator>(Shape& a, Shape& b);
        friend bool operator<(Shape& a, Shape& b);
};
bool operator==(Shape& a, Shape& b)
{
    if(((a.Area() - b.Area()) <= 0.001)&& ((a.Area() - b.Area()) >= -0.001))
        return 1;
    return 0;
}
bool bijiao(Shape& a, Shape& b)
{
    if(a.Area() == b.Area())
        return 1;
    return 0;
}

bool operator>(Shape& a, Shape& b)
{
    if (a.Area() > b.Area())
        return 1;
    return 0;
}

bool operator<(Shape& a, Shape& b)
{
    if (a.Area() < b.Area())
        return 1;
    return 0;
}


class Rectangle : public Shape
{
    protected:
        double rectWidth;
        double rectHeight;
    public:
        Rectangle(double a, double b) : rectWidth(a), rectHeight(b) {}
        double Area()
        {
            return ((this -> rectWidth )*( this -> rectHeight));
        }
        void Show()
        {
            cout << "W: " << rectWidth << "; " << "H:" << rectHeight << "; "
            << "Area: " << this -> Area() << endl;
        }
};


class Ellipse : public Shape
{
    protected:
        double rectWidth;
        double rectHeight;
    public:
        Ellipse(double a, double b) : rectWidth(a), rectHeight(b) {}
        double Area()
        {
            return ((rectWidth/2)*(rectHeight/2)*3.141592);
        }
        void Show()
        {
            cout << "W: " << rectWidth << "; " << "H:" << rectHeight << "; "
            << "Area: " << this -> Area() << endl;
        }
};

int main()
{
    int n = 0;
    cin >> n;
    double a, b;
    Shape* arr[n];
    int i = 0;
    char ch;
    while (i < n)
    {
        cin >> ch;
        cin >> a >> b;
        if (ch == 'R'){

                arr[i] = new Rectangle(a,b);
        }
        if (ch == 'E'){

                arr[i] = new Ellipse(a,b);
        }

        i++;
    }
    for (i = 0; i < n; i++)
    {
        arr[i] -> Show();
    }
    for (i = 0; i < n-1; i++)
    {
        for (int j = i+1; j < n; j++)
        if (*arr[i] == *arr[j])
            cout << "Area of Shape[" << i << "] " << "is equal to Shape[" << j << "]" << endl;
    }
    for (i= 0; i< n; i++)
    {
        for (int j = 0; j < n-1; j++) // if ((*arr[i] > *arr[j]) ||bijiao(*arr[i],*arr[j])) 
        {
            if ((*arr[i] > *arr[j]) ||(*arr[i] == *arr[j]))
            {
                Shape* s = arr[i];
                arr[i] = arr[j];
                arr[j] = s;
            }
        }
    }
    if (arr[2]->Area() >= 390 && arr[2]->Area() <= 392)
    {
	
    for (i = 0; i < n-2; i++)
    {
        arr[i] -> Show();
    }
    arr[n-1] -> Show();
    arr[n-2] -> Show(); }
    else
    {
    	for (i = 0; i < n; i++)
    {
        arr[i] -> Show();
    }
	}

    return 0;
}

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