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37 lines
718 B
C++
37 lines
718 B
C++
Abstract base class
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#include <iostream>
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using namespace std;
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class CPolygon {
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protected:
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int width, height;
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public:
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void set_values (int a, int b)
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{ width=a; height=b; }
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virtual int area (void) =0;
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};
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class CRectangle: public CPolygon {
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public:
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int area (void)
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{ return (width * height); }
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};
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class CTriangle: public CPolygon {
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public:
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int area (void)
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{ return (width * height / 2); }
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};
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int main () {
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CRectangle rect;
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CTriangle trgl;
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CPolygon * ppoly1 = ▭
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CPolygon * ppoly2 = &trgl;
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ppoly1->set_values (4,5);
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ppoly2->set_values (4,5);
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cout << ppoly1->area() << endl;
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cout << ppoly2->area() << endl;
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return 0;
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}
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