Single Level Inheritance

#include <iostream>

using namespace std;

/*
 * Types:
 * 1. Single-Level Inheritance
 * 2. Multi-level
 * 3. Multiple
 * 4. Hybrid
 */

class Shape
{
private:
  float width;
  float height;

public:
  Shape()
  {
    this->width = this->height = 0.0;
  }

  Shape(float width, float height)
  {
    this->width = width;
    this->height = height;
  }

  float get_width()
  {
    return this->width;
  }

  float get_height()
  {
    return this->height;
  }

  float getArea()
  {
    return this->width * this->height;
  }
};

class Square : public Shape
{
public:
  Square() { }

  Square(float side) : Shape(side, side)
  {
  }

  float getPerimeter()
  {
    return 2 * this->get_width() + 2 * this->get_height();
  }
};

class Rectangle : public Shape
{
public:
  Rectangle() { }

  Rectangle(float width, float height) : Shape(width, height)
  {
  }

  float getPerimeter()
  {
    return 2 * (this->get_width() + this->get_height());
  }
};

int main(int argc, char const *argv[])
{
  Square s(10.0);

  cout << "Area of square is " << s.getArea() << endl;
  cout << "Perimeter of square is " << s.getPerimeter() << endl;

  Rectangle r(10, 20);

  cout << "Area of rectangle is " << r.getArea() << endl;
  cout << "Perimeter of rectangle is " << r.getPerimeter() << endl;

  return 0;
}