用c++写一个民航订票系统,使用文件储存数据，不使用链表，不使用容器，不使用数据库，包含用户和管理两个类，实现订票、改签、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，下面是一个简单的民航订票系统的C++代码，使用文件储存数据，不使用链表，不使用容器，不使用数据库，包含用户和管理两个类，实现订票、改签、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。

其中，飞机票数据存储在文件中，文件名为"flight.dat"，用户数据存储在文件中，文件名为"user.dat"。

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

using namespace std;

//航班信息
class Flight {
public:
    char flightNo[10]; //航班号
    char startPlace[20]; //起点
    char endPlace[20]; //终点
    char startTime[20]; //起飞时间
    int price; //票价
    int seats; //余票数
};

//用户信息
class User {
public:
    char username[20]; //用户名
    char password[20]; //密码
};

//管理员类
class Manager {
public:
    //增加航班信息
    void addFlight() {
        Flight flight;
        cout << "请输入航班号：" << endl;
        cin >> flight.flightNo;
        cout << "请输入起点：" << endl;
        cin >> flight.startPlace;
        cout << "请输入终点：" << endl;
        cin >> flight.endPlace;
        cout << "请输入起飞时间：" << endl;
        cin >> flight.startTime;
        cout << "请输入票价：" << endl;
        cin >> flight.price;
        cout << "请输入余票数：" << endl;
        cin >> flight.seats;
        //写入文件
        ofstream fout("flight.dat", ios::app | ios::binary);
        fout.write((char*)&flight, sizeof(Flight));
        fout.close();
        cout << "添加航班成功！" << endl;
    }

    //删除航班信息
    void deleteFlight() {
        char flightNo[10];
        cout << "请输入要删除的航班号：" << endl;
        cin >> flightNo;
        //读取文件
        ifstream fin("flight.dat", ios::binary);
        ofstream fout("temp.dat", ios::binary);
        Flight flight;
        bool flag = false;
        while (fin.read((char*)&flight, sizeof(Flight))) {
            if (strcmp(flight.flightNo, flightNo) != 0) {
                fout.write((char*)&flight, sizeof(Flight));
            }
            else {
                flag = true;
            }
        }
        fin.close();
        fout.close();
        //删除原文件，重命名临时文件
        remove("flight.dat");
        rename("temp.dat", "flight.dat");
        if (flag) {
            cout << "删除航班成功！" << endl;
        }
        else {
            cout << "未找到该航班！" << endl;
        }
    }

    //修改航班信息
    void modifyFlight() {
        char flightNo[10];
        cout << "请输入要修改的航班号：" << endl;
        cin >> flightNo;
        //读取文件
        fstream file("flight.dat", ios::in | ios::out | ios::binary);
        Flight flight;
        bool flag = false;
        while (file.read((char*)&flight, sizeof(Flight))) {
            if (strcmp(flight.flightNo, flightNo) == 0) {
                flag = true;
                cout << "请输入新的起点（原始值：" << flight.startPlace << "）：" << endl;
                cin >> flight.startPlace;
                cout << "请输入新的终点（原始值：" << flight.endPlace << "）：" << endl;
                cin >> flight.endPlace;
                cout << "请输入新的起飞时间（原始值：" << flight.startTime << "）：" << endl;
                cin >> flight.startTime;
                cout << "请输入新的票价（原始值：" << flight.price << "）：" << endl;
                cin >> flight.price;
                cout << "请输入新的余票数（原始值：" << flight.seats << "）：" << endl;
                cin >> flight.seats;
                //写回文件
                file.seekp(-sizeof(Flight), ios::cur);
                file.write((char*)&flight, sizeof(Flight));
                break;
            }
        }
        file.close();
        if (flag) {
            cout << "修改航班成功！" << endl;
        }
        else {
            cout << "未找到该航班！" << endl;
        }
    }

    //显示所有航班信息
    void displayAllFlight() {
        ifstream fin("flight.dat", ios::binary);
        Flight flight;
        cout << "航班号\t起点\t终点\t起飞时间\t票价\t余票数" << endl;
        while (fin.read((char*)&flight, sizeof(Flight))) {
            cout << flight.flightNo << "\t" << flight.startPlace << "\t" << flight.endPlace << "\t" << flight.startTime << "\t" << flight.price << "\t" << flight.seats << endl;
        }
        fin.close();
    }
};

//用户类
class Customer {
public:
    char username[20]; //用户名
    int flightIndex; //航班索引
    int seatNo; //座位号

    //订票
    void bookTicket() {
        Flight flight;
        char flightNo[10];
        cout << "请输入航班号：" << endl;
        cin >> flightNo;
        //读取文件
        ifstream fin("flight.dat", ios::binary);
        bool flag = false;
        int index = 0;
        while (fin.read((char*)&flight, sizeof(Flight))) {
            if (strcmp(flight.flightNo, flightNo) == 0) {
                flag = true;
                if (flight.seats <= 0) {
                    cout << "该航班余票不足！" << endl;
                    return;
                }
                flight.seats--;
                //修改文件
                fstream file("flight.dat", ios::in | ios::out | ios::binary);
                file.seekp(index * sizeof(Flight), ios::beg);
                file.write((char*)&flight, sizeof(Flight));
                file.close();
                //写入文件
                ofstream fout("user.dat", ios::app | ios::binary);
                Customer customer;
                strcpy(customer.username, username);
                customer.flightIndex = index;
                customer.seatNo = 100 - flight.seats;
                fout.write((char*)&customer, sizeof(Customer));
                fout.close();
                cout << "订票成功！座位号：" << 100 - flight.seats << endl;
                break;
            }
            index++;
        }
        fin.close();
        if (!flag) {
            cout << "未找到该航班！" << endl;
        }
    }

    //改签
    void changeTicket() {
        Flight flight;
        char flightNo[10];
        cout << "请输入原来的航班号：" << endl;
        cin >> flightNo;
        //读取文件
        ifstream fin("flight.dat", ios::binary);
        bool flag = false;
        int index = 0;
        while (fin.read((char*)&flight, sizeof(Flight))) {
            if (strcmp(flight.flightNo, flightNo) == 0) {
                flag = true;
                cout << "该航班信息：" << endl;
                cout << "航班号\t起点\t终点\t起飞时间\t票价\t余票数" << endl;
                cout << flight.flightNo << "\t" << flight.startPlace << "\t" << flight.endPlace << "\t" << flight.startTime << "\t" << flight.price << "\t" << flight.seats << endl;
                cout << "请输入新的航班号：" << endl;
                cin >> flightNo;
                //读取文件
                ifstream fin("flight.dat", ios::binary);
                bool flag2 = false;
                int index2 = 0;
                while (fin.read((char*)&flight, sizeof(Flight))) {
                    if (strcmp(flight.flightNo, flightNo) == 0) {
                        flag2 = true;
                        if (flight.seats <= 0) {
                            cout << "该航班余票不足！" << endl;
                            return;
                        }
                        flight.seats--;
                        //修改文件
                        fstream file("flight.dat", ios::in | ios::out | ios::binary);
                        file.seekp(index2 * sizeof(Flight), ios::beg);
                        file.write((char*)&flight, sizeof(Flight));
                        file.close();
                        //修改文件
                        fstream file2("user.dat", ios::in | ios::out | ios::binary);
                        Customer customer;
                        bool flag3 = false;
                        int index3 = 0;
                        while (file2.read((char*)&customer, sizeof(Customer))) {
                            if (strcmp(customer.username, username) == 0 && customer.flightIndex == index && customer.seatNo == 100 - flight.seats) {
                                flag3 = true;
                                customer.flightIndex = index2;
                                file2.seekp(index3 * sizeof(Customer), ios::beg);
                                file2.write((char*)&customer, sizeof(Customer));
                                break;
                            }
                            index3++;
                        }
                        file2.close();
                        if (flag3) {
                            cout << "改签成功！新的座位号：" << 100 - flight.seats << endl;
                        }
                        else {
                            cout << "改签失败！" << endl;
                        }
                        break;
                    }
                    index2++;
                }
                fin.close();
                if (!flag2) {
                    cout << "未找到该航班！" << endl;
                }
                break;
            }
            index++;
        }
        fin.close();
        if (!flag) {
            cout << "未找到该航班！" << endl;
        }
    }

    //退票
    void refundTicket() {
        ifstream fin("user.dat", ios::binary);
        ofstream fout("temp.dat", ios::binary);
        Customer customer;
        bool flag = false;
        while (fin.read((char*)&customer, sizeof(Customer))) {
            if (strcmp(customer.username, username) == 0) {
                flag = true;
                //读取文件
                ifstream fin2("flight.dat", ios::binary);
                Flight flight;
                int index = 0;
                while (fin2.read((char*)&flight, sizeof(Flight))) {
                    if (index == customer.flightIndex) {
                        flight.seats++;
                        //修改文件
                        fstream file("flight.dat", ios::in | ios::out | ios::binary);
                        file.seekp(index * sizeof(Flight), ios::beg);
                        file.write((char*)&flight, sizeof(Flight));
                        file.close();
                        break;
                    }
                    index++;
                }
                fin2.close();
            }
            else {
                fout.write((char*)&customer, sizeof(Customer));
            }
        }
        fin.close();
        fout.close();
        //删除原文件，重命名临时文件
        remove("user.dat");
        rename("temp.dat", "user.dat");
        if (flag) {
            cout << "退票成功！" << endl;
        }
        else {
            cout << "未找到该用户！" << endl;
        }
    }

    //查询航班信息
    void queryFlight() {
        char flightNo[10];
        cout << "请输入航班号：" << endl;
        cin >> flightNo;
        //读取文件
        ifstream fin("flight.dat", ios::binary);
        Flight flight;
        bool flag = false;
        while (fin.read((char*)&flight, sizeof(Flight))) {
            if (strcmp(flight.flightNo, flightNo) == 0) {
                flag = true;
                cout << "航班号\t起点\t终点\t起飞时间\t票价\t余票数" << endl;
                cout << flight.flightNo << "\t" << flight.startPlace << "\t" << flight.endPlace << "\t" << flight.startTime << "\t" << flight.price << "\t" << flight.seats << endl;
                break;
            }
        }
        fin.close();
        if (!flag) {
            cout << "未找到该航班！" << endl;
        }
    }

    //查询订单信息
    void queryOrder() {
        ifstream fin("user.dat", ios::binary);
        Customer customer;
        bool flag = false;
        while (fin.read((char*)&customer, sizeof(Customer))) {
            if (strcmp(customer.username, username) == 0) {
                flag = true;
                //读取文件
                ifstream fin2("flight.dat", ios::binary);
                Flight flight;
                int index = 0;
                while (fin2.read((char*)&flight, sizeof(Flight))) {
                    if (index == customer.flightIndex) {
                        cout << "航班号\t起点\t终点\t起飞时间\t票价\t座位号" << endl;
                        cout << flight.flightNo << "\t" << flight.startPlace << "\t" << flight.endPlace << "\t" << flight.startTime << "\t" << flight.price << "\t" << customer.seatNo << endl;
                        break;
                    }
                    index++;
                }
                fin2.close();
            }
        }
        fin.close();
        if (!flag) {
            cout << "未找到该用户！" << endl;
        }
    }
};

int main() {
    int choice;
    cout << "请选择身份：" << endl;
    cout << "1. 管理员" << endl;
    cout << "2. 用户" << endl;
    cin >> choice;
    //管理员
    if (choice == 1) {
        Manager manager;
        while (true) {
            cout << endl;
            cout << "请选择操作：" << endl;
            cout << "1. 增加航班信息" << endl;
            cout << "2. 删除航班信息" << endl;
            cout << "3. 修改航班信息" << endl;
            cout << "4. 显示所有航班信息" << endl;
            cout << "0. 退出系统" << endl;
            cin >> choice;
            switch (choice) {
            case 1:
                manager.addFlight();
                break;
            case 2:
                manager.deleteFlight();
                break;
            case 3:
                manager.modifyFlight();
                break;
            case 4:
                manager.displayAllFlight();
                break;
            case 0:
                return 0;
            default:
                cout << "输入错误，请重新输入！" << endl;
                break;
            }
        }
    }
    //用户
    else if (choice == 2) {
        Customer customer;
        cout << "请输入用户名：" << endl;
        cin >> customer.username;
        while (true) {
            cout << endl;
            cout << "请选择操作：" << endl;
            cout << "1. 订票" << endl;
            cout << "2. 改签" << endl;
            cout << "3. 退票" << endl;
            cout << "4. 查询航班信息" << endl;
            cout << "5. 查询订单信息" << endl;
            cout << "0. 退出系统" << endl;
            cin >> choice;
            switch (choice) {
            case 1:
                customer.bookTicket();
                break;
            case 2:
                customer.changeTicket();
                break;
            case 3:
                customer.refundTicket();
                break;
            case 4:
                customer.queryFlight();
                break;
            case 5:
                customer.queryOrder();
                break;
            case 0:
                return 0;
            default:
                cout << "输入错误，请重新输入！" << endl;
                break;
            }
        }
    }
    //输入错误
    else {
        cout << "输入错误！" << endl;
        return 0;
    }
    return 0;
}