#include <iostream>
#include <vector>
#include <string>

struct contact {
    std::string name;
    std::string mobile;
    std::string address;
    std::string email;
};

void menu() {
    std::cout << "\t\t\tCONTACTS\t\t\t" << std::endl;
    std::cout << "1) New a contact " << std::endl;
    std::cout << "2) See a contact " << std::endl;
    std::cout << "3) Delete a contact " << std::endl;
    std::cout << "3) Change a contact " << std::endl;
}

int main() {
    int k = 0;
    int j = 0;
    int q = 0;
    int z = 0;
    int n_change = 0;
    std::vector <contact> user;

    while (true) {
        menu();
        while (true) {
            std::string a;
            getline(std::cin, a);
            //добавление контакта
            if (a == "1") {
                k++;
                user.resize(k);
                std::cout << "\nNAME: ";
                getline(std::cin, user[q].name);

                std::cout << "\nMOBILE: ";
                getline(std::cin, user[q].mobile);

                std::cout << "\nADDRESS: ";
                getline(std::cin, user[q].address);

                std::cout << "\nEMAIL: ";
                getline(std::cin, user[q].email);

                //проверка памяти 1
                //std::cout << "Fist size: " << user.size() << std::endl;

                if (user[q].name.empty()) {
                    if (user[q].mobile.empty()) {
                        if (user[q].address.empty()) {
                            if (user[q].email.empty()) {
                                z++;
                                user.resize(k - z);
                            }
                        }
                    }

                }
                //проверка памяти 2
                //std::cout << "Second size: " << user.size() << std::endl;

                j++;
                q++;

            }
            menu();
            //удаление контакта
            if (a == "3") {
                int n = 0;
                std::cout << "Which contact do you wanna delete? (" << 0 << "to" << k - 1 << ")";
                std::cin >> n;
                std::cout << "Fist size: " << user.size() << std::endl;
                user.erase(user.begin() + n);
                std::cout << "Second size: " << user.size() << std::endl;
                k--;
                menu();
            }
            //просмотр контактов
            if (a == "2") {
                std::cout << "\t-------------\n";
                std::cout << "\tYOUR CONTACTS\n";
                std::cout << "\-------------\n";
                for (int i = 0; i < k; i++) {
                    std::cout << "Number " << i << std::endl;
                    std::cout << "\-------------\n";
                    std::cout << "N: " << user[i].name << std::endl;
                    std::cout << "M: " << user[i].mobile << std::endl;
                    std::cout << "A: " << user[i].address << std::endl;
                    std::cout << "E: " << user[i].email << std::endl;
                    std::cout << "---------------\n" << std::endl;
                }
            }
            //изменение контакта
            if (a == "4") {
                std::cout << "\nThe number of the contact which you want change: ";
                std::cin >> n_change;
                struct c_contact {
                    std::string name;
                    std::string mobile;
                    std::string address;
                    std::string email;
                };
                c_contact c_user;
                std::cout << "\nName: ";
                getline(std::cin,c_user.name);
                std::cout << "\nMobile: ";
                getline(std::cin, c_user.mobile);
                std::cout << "\nAddress: ";
                getline(std::cin, c_user.address);
                std::cout << "\nE-mail: ";
                getline(std::cin, c_user.email);

            }

        }

    }
    return 0;
}