Tiplarni dinamik tarzda

1.4-dastur. Dinamik tipdagi identifikatsiya vositasidan foydalanish.
#include "stdafx.h"
#include
#include
#include
using namespace std;
class figure {
protected:
double x, y; public:
figure(double i, double j) { x = i;
y = j;
}
virtual double area() = 0;
};
class triangle : public figure { public:
triangle(double i, double j) : figure(i, j) {} double area() {
return x * 0.5 * y;
}
};
class rectangle : public figure { public:
rectangle(double i, double j) : figure (i, j) {} double area() { return x * y;}
};
class circle : public figure { public:
circle(double i, double j=0) : figure(i, j) {} double area() {return 3.14 * x * x;}
};
// figure sinf obʻyektlarini yaratish. figure *factory(){
switch(rand() % 3 ) {
case 0: return new circle (rand()%15);
case 1: return new triangle (rand()%15,rand()%15); case 2: return new rectangle (rand()%15, rand()%15);
}
return 0;
};
int main(){
figure *p; // asos sinfga koʻrsatkich int i;
int t=0, r=0, c=0;
// 5 ta obʻyektlarni hosil qilsh va sanash for(i=0; i<15; i++) {
p = factory(); // obʻyektni hosil qilish
cout << "Obʻyektning tipi: " << typeid(*p).name(); cout << ". ";
// obʻyektni tekshirish orqali sanasj if(typeid(*p) == typeid(triangle)) t++; if(typeid(*p) == typeid(rectangle)) r++; if(typeid(*p) == typeid(circle)) c++;
// Yuzasini hisoblash
cout << " S= " << p->area() << endl;
}
cout << endl;
cout << "Quyidagi obʻyektlar hosil qilindi:\n"; cout << " Uchburchaklar: " << t << endl;
cout << " Toʻrtburchaklar: " << r << endl; cout << " Doiralar: " << c << endl; system("pause");
return 0;
}
1.4 – dastur natijasi. Output
Obʻyektning tipi: class rectangle. S= 8 Obʻyektning tipi: class triangle. S= 28 Obʻyektning tipi: class circle. S= 28.26 Obʻyektning tipi: class triangle. S= 35 Obʻyektning tipi: class rectangle. S= 12 Obʻyektning tipi: class triangle. S= 55 Obʻyektning tipi: class rectangle. S= 72 Obʻyektning tipi: class circle. S= 254.34 Obʻyektning tipi: class rectangle. S= 21 Obʻyektning tipi: class triangle. S= 33 Obʻyektning tipi: class rectangle. S= 10 Obʻyektning tipi: class circle. S= 379.94 Obʻyektning tipi: class circle. S= 254.34 Obʻyektning tipi: class triangle. S= 4 Obʻyektning tipi: class triangle. S= 36
Quyidagi obʻyektlar hosil qilindi: Uchburchaklar: 6
Toʻrtburchaklar: 5
Doiralar: 4