Test.cpp

#include <iostream>
#include <string>
using namespace std;
const int MAX = 100;

template<typename T,typename F>
int myfind(T* begin,T* end,F f) {
    for (T* itr = begin; itr != end; itr++) {

       ?

    }
    return -1;

}

class AbstractUser {
public:
    AbstractUser(const string& username, const string& password)
        : username(username), password(password) {}

    virtual ~AbstractUser() = default;

    virtual void displayRole() const = 0;
    virtual bool hasAccessToSee(AbstractUser*) const = 0;

    string getUsername() const {
        return username;
    }
    bool isPasswordCorrect(const string& pass) {
        return (pass == password);
    }

protected:
    string username;
    string password;
};

class Student : public AbstractUser {
public:
    Student(const string& username, const string& password, int grade)
        : AbstractUser(username, password), grade(grade) {}

    void displayRole() const override {
        cout << "Student: " << username << ", Grade: " << grade << endl;
    }
    bool hasAccessToSee(AbstractUser* user) const override {
        return false;//doesnt have access for any type
    }

private:
    int grade;
};

class Staff : public AbstractUser {
public:
    Staff(const string& username, const string& password, int salary)
        : AbstractUser(username, password), salary(salary) {}

    void displayRole() const override {
        cout << "Staff: " << username << ", Salary: " << salary << endl;
    }
    bool hasAccessToSee(AbstractUser* user) const override {
        if (? != nullptr) {
            return true;
        }
    }

private:
    int salary;
};

class Admin : public Staff {
public:
    Admin(const string& username, const string& password, int salary)
        : Staff(username, password, salary) {}

    void displayRole() const override {

        cout << "Admin ";
        Staff::displayRole();
    }
    ?
};

AbstractUser* current_user;
AbstractUser* users[100];
int user_cnt;

void print() {
    if (!current_user) {
        return;
    }
    for (AbstractUser* user : users) {
        if (?) {
            user->displayRole();
        }
    }
}

void addStudent(string username, string password, int grade) {
    int index = ?;
    if (index != -1) {
        return;
    }
    if (dynamic_cast<Admin*>(current_user) == nullptr){
        cout << "permision denied"<<endl;
        return;
    }
    Student* st = new Student(username, password, grade);
    users[user_cnt ++] = st;
}

int main() {
    Student s("erfan", "pass1", 12);
    Student s2("rasool", "pass2", 12);
    Staff st("alireza", "staffpass", 1000);
    Staff st("kiyan", "staffpass", 1000);
    Admin a("yalda", "adminpass",1200);
    user_cnt = 5;
    users[0] = &s;
    ?
    ?
    ?
    ?

    while (1) {
        string username, password;
        cout << "username: ";
        cin >> username;
        cout << "password:";
        cin >> password;
        int index = myfind(users, users + user_cnt, ?);
        if (index!=-1) {
            current_user = users[index];
            break;
        }

    }
    int choice;
    while (1) {
        cout << "1.print" << endl;
        cout<<"2.add student"<<endl;
        cin >> choice;
        if (choice == 1) {
            print();
        }
        else {
            string user, pass;
            int grade;
            cin >> user >> pass >> grade;
            addStudent(user, pass, grade);

        }

    }

    return 0;
}