#include <iostream>
#include <memory>
#include <vector>

using namespace std;

class Car {
public:
    Car(int price) : price_(price) {}
    int getPrice() const {
        return price_;
    }
    void sell() const {
        cout << "sell a car for : " << price_ <<  endl;
    }
private:
    int price_;
};
class CarSelector {
public:
    CarSelector();
    virtual ~CarSelector() = 0;
    virtual bool ShouldSelect (const Car& car) const = 0;
};
class HighStandardCarSelector:public CarSelector {
public:
    bool ShouldSelect (const Car& car) const {
        if (car.getPrice() > 100000) {
            return true;
        } else {
            return false;
        }
    }
};
class LowStandardCarSelector:public CarSelector {
public:
    bool ShouldSelect (const Car& car) const {
        if (car.getPrice() <= 100000) {
            return true;
        } else {
            return false;
        }
    }
};
class CarDealer {
public :
    const Car* Suggest(const CarSelector& selector) {
      for (const Car& car: inventory_) {
        if (selector.ShouldSelect(car)) return &car;
      }
      return nullptr ;
    }
  private :
  std::vector <Car> inventory_;
};

class MyClient {
public:
    void BuyCar() {
        CarDealer dealer;
        HighStandardCarSelector high_selector();
        const Car* candidate = dealer.Suggest(high_selector);
        if (candidate == nullptr ) {
            LowStandardCarSelector low_selector ( /* params */ );
            candidate = dealer.Suggest(low_selector);
        }
    }
};
int main() {
    return 0;
}