// ********** ObserverDemo.cpp **********
#include <iostream>
#include <time.h>
using namespace std;

class Observable;
class Observer { public: virtual void update(Observable* o) = 0; };

const int MAX_OBS = 500;
class Observable {
  private:
    Observer* observers[MAX_OBS];
    int num_observers;
  public:
    Observable() { num_observers = 0; }
    void addObserver(Observer* o) {
      if (num_observers < MAX_OBS) 
        observers[num_observers++] = o;
    }
    void notifyObservers() {
      for (int i=0; i<num_observers; i++) {
        observers[i]->update(this);
      }
    }
};
class Observable1 : public Observable {
  private:
    int value;
  public:
    Observable1() { value = 0; }
    int getValue() { return value; }
    void setValue(int newvalue) { value = newvalue; notifyObservers(); }
};
class Observer1 : public Observer {
   public:
     void update(Observable* o) { int value = ((Observable1*)o)->getValue();  }
};
int main() {
    hrtime_t t1 = gethrtime();
    Observer1* observers[MAX_OBS];
    Observable1* observables[MAX_OBS];
    for (int i=0; i<MAX_OBS; i++) 
      observers[i] = new Observer1();
    for (int j=0; j<MAX_OBS; j++) {
      observables[j] = new Observable1();
      for (int i=0; i<MAX_OBS; i++) 
        observables[j]->addObserver(observers[i]);
    }
    for (int k=0; k<100; k++)  
      for (int j=0; j<MAX_OBS; j++) 
         observables[j]->setValue(k); 

  hrtime_t t2 = gethrtime();
  cout << (t2-t1)/1000000 << " ";
  return 1;
}