navigator.cpp

#include <iostream>
#include <memory>
#include <string>
using namespace std; 

class RouteStrategy {
public:
    virtual ~RouteStrategy() = default;
    virtual void buildRoute(const string& A, const string& B) = 0;
};

class RoadStrategy : public RouteStrategy {
public:
    void buildRoute(const string& A, const string& B) override {
        cout << "Building route by car from " << A << " to " << B << endl;
    }
};

class WalkingStrategy : public RouteStrategy {
public:
    void buildRoute(const string& A, const string& B) override {
        cout << "Building walking route from " << A << " to " << B << endl;
    }
};

class PublicTransportStrategy : public RouteStrategy {
public:
    void buildRoute(const string& A, const string& B) override {
        cout << "Building public transport route from " << A << " to " << B << endl;
    }
};

class Navigator {
private:
    unique_ptr<RouteStrategy> routeStrategy;
public:
    void setStrategy(unique_ptr<RouteStrategy> strategy) {
        routeStrategy = move(strategy);
    }

    void buildRoute(const string& A, const string& B) {
        if (routeStrategy) {
            routeStrategy->buildRoute(A, B);
        }
        else {
            cout << "No route strategy selected!" << endl;
        }
    }
};

int main() {
    Navigator navigator;

    navigator.setStrategy(make_unique<RoadStrategy>());
    navigator.buildRoute("Odessa", "Kyiv");

    navigator.setStrategy(make_unique<WalkingStrategy>());
    navigator.buildRoute("Park", "Museum");

    navigator.setStrategy(make_unique<PublicTransportStrategy>());
    navigator.buildRoute("Station", "University");

    return 0;
}