class strategy {
protected:
public:
    virtual void initialize(long *x);  // set x to something; caller must call
    virtual long choose_time(long *x) = 0;  // there was a conflict; gimme a time
    virtual void was_successful(long *x);  // if needed, note success
};

class strategy1 : public strategy {
public:
    virtual long choose_time(long *x);
};

class strategy2 : public strategy {
public:
    virtual long choose_time(long *x);
};

class strategy3 : public strategy {
public:
    virtual long choose_time(long *x);
};

class strategy4 : public strategy {
public:
    virtual void initialize(long *x);
    virtual long choose_time(long *x);
    virtual void was_successful(long *x);
};

class strategy5 : public strategy {
public:
    virtual void initialize(long *x);
    virtual long choose_time(long *x);
    virtual void was_successful(long *x);
};