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/* File : example.h */
class Shape
{
public:
Shape ()
{
nshapes++;
}
virtual ~ Shape ()
{
nshapes--;
};
double x, y;
void move (double dx, double dy);
virtual double area (void) const = 0;
virtual double perimeter (void) const = 0;
protected:
static int nshapes;
};
class Circle:public Shape
{
private:
double radius;
public:
Circle (double r):radius (r)
{
};
virtual double area (void) const;
virtual double perimeter (void) const;
};
class Square:public Shape
{
private:
double width;
public:
Square (double w):width (w)
{
};
virtual double area (void) const;
virtual double perimeter (void) const;
};
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