Answer to Question #319984 in C++ for Yaku

Question

Consider the abstract class declaration:

class aPolygon

{

protected:

long double * sides, // There are N sides with different lengths

* angles; // There are N angles with different sizes

long int no_of_sides; // The number of sides, N, of this polygon

public: aPolygon(long int _sides = 1);

/* It sets no_of_sides = _sides.*/

virtual void input () = 0; // input the derived polygon

virtual void display () = 0; // display the derived polygon

~aPolygon() {}

};

Write a complete C++ class implementation of the following derived class, aSquare, with the class interface::

class aSquare : public aPolygon

{

public:

aSquare(); /* It creates a square as a unit square */

~aSquare() {}

virtual void input(); /* It inputs the data for the square */

virtual void display(); /* It displays the square: angles, sides, perimeter and area */

long double perimeter(); /* It computes the perimeter of the square */

long double area(); /* It computes the area of the square: */

}; 

Answer 1

#include <iostream>
using namespace std;


class aPolygon
{
protected:
    long double * sides, // There are N sides with different lengths
                * angles; // There are N angles with different sizes
    long int no_of_sides; // The number of sides, N, of this polygon


public: 
    aPolygon(long int _sides = 1);
    /* It sets no_of_sides = _sides.*/


    virtual void input () = 0; // input the derived polygon
    virtual void display () = 0; // display the derived polygon
    ~aPolygon();
}; 


aPolygon::aPolygon(long int _sides)
{
    no_of_sides = _sides;
    sides = new long double[no_of_sides];
    angles = new long double[no_of_sides];
}


aPolygon::~aPolygon() {
    delete [] sides;
    delete [] angles;
}


class aSquare : public aPolygon
{
public:
    aSquare(); /* It creates a square as a unit square */
    ~aSquare() {}


    virtual void input(); /* It inputs the data for the square */
    virtual void display(); /* It displays the square: angles, sides, perimeter and area */
    long double perimeter(); /* It computes the perimeter of the square */
    long double area(); /* It computes the area of the square: */
}; 


aSquare::aSquare() : aPolygon(4)
{
    for (int i=0; i<4; i++) {
        sides[i] = 1.0;
        angles[i] = 90;
    }
}


void aSquare::input()
{
    cout << "Enter a side length of a square: ";
    long double a;
    cin >> a;
    for (int i=0; i<4; i++) {
        sides[i] = a;
    }
}


void aSquare::display()
{
    cout << "Square: sides = " << sides[0] << "; angles = "
         << angles[0] << " deg" << endl;
}


long double aSquare::perimeter() {
    return 4 * sides[0];
}


long double aSquare::area() {
    return sides[0] * sides[0];
}


int main() {
    aSquare sq;


    sq.input();
    cout << endl;
    sq.display();
    cout << "Perimeter = " << sq.perimeter() << endl;
    cout << "Area = " << sq.area() << endl;


    return 0;
}