用c++写一个民航订票系统,使用文件储存数据，不使用链表、容器、数据库，包含用户和管理两个类，实现订票、退票、查询航班、增加航班、删除航班、修改航班、显示航班等功能。

好的，这是一个挑战性比较大的任务，需要耐心和细心地编写代码。下面是一个简单的实现，仅供参考。

#include <iostream>
#include <fstream>
#include <cstring>

using namespace std;

class User {
public:
    string name;
    int age;
    string id;
    string phone;

    User(string name, int age, string id, string phone) {
        this->name = name;
        this->age = age;
        this->id = id;
        this->phone = phone;
    }
};

class Flight {
public:
    string id;
    string start;
    string end;
    string date;
    int price;
    int seat;

    Flight(string id, string start, string end, string date, int price, int seat) {
        this->id = id;
        this->start = start;
        this->end = end;
        this->date = date;
        this->price = price;
        this->seat = seat;
    }
};

class Manager {
public:
    void addFlight(string id, string start, string end, string date, int price, int seat) {
        ofstream outfile("flight.txt", ios::app);
        outfile << id << " " << start << " " << end << " " << date << " " << price << " " << seat << endl;
        outfile.close();
    }

    void deleteFlight(string id) {
        ifstream infile("flight.txt");
        ofstream outfile("temp.txt", ios::trunc);
        string fid, start, end, date, str;
        int price, seat;
        while (infile >> fid >> start >> end >> date >> price >> seat) {
            if (fid != id) {
                outfile << fid << " " << start << " " << end << " " << date << " " << price << " " << seat << endl;
            }
        }
        infile.close();
        outfile.close();
        remove("flight.txt");
        rename("temp.txt", "flight.txt");
    }

    void modifyFlight(string id, string start, string end, string date, int price, int seat) {
        ifstream infile("flight.txt");
        ofstream outfile("temp.txt", ios::trunc);
        string fid, s, e, d, str;
        int p, s1;
        while (infile >> fid >> s >> e >> d >> p >> s1) {
            if (fid == id) {
                outfile << id << " " << start << " " << end << " " << date << " " << price << " " << seat << endl;
            } else {
                outfile << fid << " " << s << " " << e << " " << d << " " << p << " " << s1 << endl;
            }
        }
        infile.close();
        outfile.close();
        remove("flight.txt");
        rename("temp.txt", "flight.txt");
    }

    void showFlight() {
        ifstream infile("flight.txt");
        string id, start, end, date, str;
        int price, seat;
        while (infile >> id >> start >> end >> date >> price >> seat) {
            cout << id << " " << start << " " << end << " " << date << " " << price << " " << seat << endl;
        }
        infile.close();
    }
};

class Customer {
public:
    User user;

    Customer(string name, int age, string id, string phone) {
        user = User(name, age, id, phone);
    }

    void queryFlight(string start, string end, string date) {
        ifstream infile("flight.txt");
        string id, s, e, d, str;
        int p, s1;
        while (infile >> id >> s >> e >> d >> p >> s1) {
            if (s == start && e == end && d == date && s1 > 0) {
                cout << id << " " << start << " " << end << " " << date << " " << p << endl;
            }
        }
        infile.close();
    }

    void bookFlight(string id) {
        ifstream infile("flight.txt");
        ofstream outfile("temp.txt", ios::trunc);
        string fid, start, end, date, str;
        int price, seat;
        bool find = false;
        while (infile >> fid >> start >> end >> date >> price >> seat) {
            if (fid == id) {
                if (seat > 0) {
                    outfile << fid << " " << start << " " << end << " " << date << " " << price << " " << seat - 1 << endl;
                    find = true;
                } else {
                    cout << "The flight is full." << endl;
                    outfile << fid << " " << start << " " << end << " " << date << " " << price << " " << seat << endl;
                }
            } else {
                outfile << fid << " " << start << " " << end << " " << date << " " << price << " " << seat << endl;
            }
        }
        infile.close();
        outfile.close();
        if (find) {
            remove("flight.txt");
            rename("temp.txt", "flight.txt");
        } else {
            remove("temp.txt");
        }
    }

    void refundFlight(string id) {
        ifstream infile("flight.txt");
        ofstream outfile("temp.txt", ios::trunc);
        string fid, start, end, date, str;
        int price, seat;
        bool find = false;
        while (infile >> fid >> start >> end >> date >> price >> seat) {
            if (fid == id) {
                outfile << fid << " " << start << " " << end << " " << date << " " << price << " " << seat + 1 << endl;
                find = true;
            } else {
                outfile << fid << " " << start << " " << end << " " << date << " " << price << " " << seat << endl;
            }
        }
        infile.close();
        outfile.close();
        if (find) {
            remove("flight.txt");
            rename("temp.txt", "flight.txt");
        } else {
            remove("temp.txt");
        }
    }
};

int main() {
    Manager manager;
    Customer customer("Tom", 20, "123456", "123456789");
    string id, start, end, date;
    int price, seat;
    int choice;
    while (true) {
        cout << "1. Add flight" << endl;
        cout << "2. Delete flight" << endl;
        cout << "3. Modify flight" << endl;
        cout << "4. Show flight" << endl;
        cout << "5. Query flight" << endl;
        cout << "6. Book flight" << endl;
        cout << "7. Refund flight" << endl;
        cout << "0. Quit" << endl;
        cout << "Enter your choice: ";
        cin >> choice;
        switch (choice) {
            case 1:
                cout << "Enter the flight id: ";
                cin >> id;
                cout << "Enter the start city: ";
                cin >> start;
                cout << "Enter the end city: ";
                cin >> end;
                cout << "Enter the date: ";
                cin >> date;
                cout << "Enter the price: ";
                cin >> price;
                cout << "Enter the seat: ";
                cin >> seat;
                manager.addFlight(id, start, end, date, price, seat);
                break;
            case 2:
                cout << "Enter the flight id: ";
                cin >> id;
                manager.deleteFlight(id);
                break;
            case 3:
                cout << "Enter the flight id: ";
                cin >> id;
                cout << "Enter the start city: ";
                cin >> start;
                cout << "Enter the end city: ";
                cin >> end;
                cout << "Enter the date: ";
                cin >> date;
                cout << "Enter the price: ";
                cin >> price;
                cout << "Enter the seat: ";
                cin >> seat;
                manager.modifyFlight(id, start, end, date, price, seat);
                break;
            case 4:
                manager.showFlight();
                break;
            case 5:
                cout << "Enter the start city: ";
                cin >> start;
                cout << "Enter the end city: ";
                cin >> end;
                cout << "Enter the date: ";
                cin >> date;
                customer.queryFlight(start, end, date);
                break;
            case 6:
                cout << "Enter the flight id: ";
                cin >> id;
                customer.bookFlight(id);
                break;
            case 7:
                cout << "Enter the flight id: ";
                cin >> id;
                customer.refundFlight(id);
                break;
            case 0:
                exit(0);
            default:
                cout << "Invalid choice." << endl;
                break;
        }
    }
    return 0;
}

这个程序使用文件来储存数据，可以对航班进行增加、删除、修改、显示的操作，也可以对航班进行查询、订票、退票的操作。程序中使用了 Manager 和 Customer 两个类来分别实现管理员和顾客的功能。但这个程序还有很多不足之处，比如没有输入校验，没有异常处理等等。