inheretance_example.cpp

inheretance_example.cpp

#include <stdint.h>
#include <stdio.h>

struct Shape {
  Shape(int64_t x, int64_t y): x(x), y(y) {}
  virtual int64_t area() {return 0;}
  int64_t x, y;
};

struct Rectangle : public Shape {
  Rectangle(int64_t x, int64_t y, int64_t w, int64_t h): Shape(x, y), w(w), h(h) {}
  virtual int64_t area() {return w*h;}
  int64_t w, h;
};

struct Circle : public Shape {
  Circle(int64_t x, int64_t y, int64_t r): Shape(x, y), r(r) {}
  virtual int64_t area() {return 3*r*r;}
  int64_t r;
};

int main(int argc, char **argv) {
  int64_t sum = 0;

  Rectangle *r = new Rectangle(1,2,3,4);
  Circle *c = new Circle(5,6,7);
  Shape* sr = static_cast<Shape*>(r);
  Shape* sc = static_cast<Shape*>(c);
  for(int64_t i=1;i<=100000000;++i) {
    sum += sr->area() + sc->area();
  }
  delete r;
  delete c;
  printf("%ld\n", sum);
  return 0;
}