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，包含用户和管理两个类，实现预订机票、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，下面是一个简单的实现，仅供参考：

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

using namespace std;

const int MAX_FLIGHTS = 100; // 最大航班数
const int MAX_NAME_LEN = 20; // 最大姓名长度
const int MAX_TICKET_NUM = 5; // 最大订票数

// 航班信息结构体
struct Flight {
    int flightNo; // 航班号
    char departureCity[MAX_NAME_LEN]; // 出发城市
    char destinationCity[MAX_NAME_LEN]; // 目的地城市
    int departureTime; // 出发时间
    int arrivalTime; // 到达时间
    int price; // 价格
    int seatNum; // 座位数
    int bookedSeatNum; // 已预订座位数
};

// 用户信息结构体
struct User {
    char name[MAX_NAME_LEN]; // 姓名
    int flightNo[MAX_TICKET_NUM]; // 订票的航班号
    int ticketNum; // 订票数
};

// 管理类
class Management {
public:
    Management() {
        flightNum = 0;
        userNum = 0;
        // 从文件中读取航班信息
        ifstream infile("flights.txt");
        if (infile) {
            while (infile >> flights[flightNum].flightNo 
                   >> flights[flightNum].departureCity 
                   >> flights[flightNum].destinationCity 
                   >> flights[flightNum].departureTime 
                   >> flights[flightNum].arrivalTime 
                   >> flights[flightNum].price 
                   >> flights[flightNum].seatNum 
                   >> flights[flightNum].bookedSeatNum) {
                flightNum++;
            }
            infile.close();
        }
        // 从文件中读取用户信息
        infile.open("users.txt");
        if (infile) {
            while (infile >> users[userNum].name) {
                infile >> users[userNum].ticketNum;
                for (int i = 0; i < users[userNum].ticketNum; i++) {
                    infile >> users[userNum].flightNo[i];
                }
                userNum++;
            }
            infile.close();
        }
    }
    ~Management() {
        // 将航班信息和用户信息保存到文件
        ofstream outfile("flights.txt");
        if (outfile) {
            for (int i = 0; i < flightNum; i++) {
                outfile << flights[i].flightNo << " " 
                        << flights[i].departureCity << " " 
                        << flights[i].destinationCity << " " 
                        << flights[i].departureTime << " " 
                        << flights[i].arrivalTime << " " 
                        << flights[i].price << " " 
                        << flights[i].seatNum << " " 
                        << flights[i].bookedSeatNum << endl;
            }
            outfile.close();
        }
        outfile.open("users.txt");
        if (outfile) {
            for (int i = 0; i < userNum; i++) {
                outfile << users[i].name << " " << users[i].ticketNum << " ";
                for (int j = 0; j < users[i].ticketNum; j++) {
                    outfile << users[i].flightNo[j] << " ";
                }
                outfile << endl;
            }
            outfile.close();
        }
    }
    void displayFlights() const {
        cout << "航班号 出发城市 目的地城市 出发时间 到达时间 价格 座位数 已预订数" << endl;
        for (int i = 0; i < flightNum; i++) {
            cout << flights[i].flightNo << " " 
                 << flights[i].departureCity << " " 
                 << flights[i].destinationCity << " " 
                 << flights[i].departureTime << " " 
                 << flights[i].arrivalTime << " " 
                 << flights[i].price << " " 
                 << flights[i].seatNum << " " 
                 << flights[i].bookedSeatNum << endl;
        }
    }
    void addFlight() {
        if (flightNum >= MAX_FLIGHTS) {
            cout << "航班数已达上限，无法添加！" << endl;
            return;
        }
        Flight flight;
        cout << "请输入航班号：";
        cin >> flight.flightNo;
        cout << "请输入出发城市：";
        cin >> flight.departureCity;
        cout << "请输入目的地城市：";
        cin >> flight.destinationCity;
        cout << "请输入出发时间（如 830 表示 8:30）：";
        cin >> flight.departureTime;
        cout << "请输入到达时间（如 1230 表示 12:30）：";
        cin >> flight.arrivalTime;
        cout << "请输入价格：";
        cin >> flight.price;
        cout << "请输入座位数：";
        cin >> flight.seatNum;
        flight.bookedSeatNum = 0;
        flights[flightNum] = flight;
        flightNum++;
        cout << "添加成功！" << endl;
    }
    void deleteFlight() {
        int flightNo;
        cout << "请输入要删除的航班号：";
        cin >> flightNo;
        int i = 0;
        for (; i < flightNum; i++) {
            if (flights[i].flightNo == flightNo) {
                // 将数组后面的元素向前移动
                for (int j = i + 1; j < flightNum; j++) {
                    flights[j - 1] = flights[j];
                }
                flightNum--;
                cout << "删除成功！" << endl;
                return;
            }
        }
        if (i == flightNum) {
            cout << "未找到要删除的航班！" << endl;
        }
    }
    void modifyFlight() {
        int flightNo;
        cout << "请输入要修改的航班号：";
        cin >> flightNo;
        for (int i = 0; i < flightNum; i++) {
            if (flights[i].flightNo == flightNo) {
                cout << "请输入出发城市（原来为 " << flights[i].departureCity << "）：";
                cin >> flights[i].departureCity;
                cout << "请输入目的地城市（原来为 " << flights[i].destinationCity << "）：";
                cin >> flights[i].destinationCity;
                cout << "请输入出发时间（原来为 " << flights[i].departureTime << "）：";
                cin >> flights[i].departureTime;
                cout << "请输入到达时间（原来为 " << flights[i].arrivalTime << "）：";
                cin >> flights[i].arrivalTime;
                cout << "请输入价格（原来为 " << flights[i].price << "）：";
                cin >> flights[i].price;
                cout << "请输入座位数（原来为 " << flights[i].seatNum << "）：";
                cin >> flights[i].seatNum;
                cout << "修改成功！" << endl;
                return;
            }
        }
        cout << "未找到要修改的航班！" << endl;
    }
    void bookTicket() {
        char name[MAX_NAME_LEN];
        int flightNo;
        cout << "请输入您的姓名：";
        cin >> name;
        cout << "请输入要订票的航班号：";
        cin >> flightNo;
        int i = 0;
        for (; i < flightNum; i++) {
            if (flights[i].flightNo == flightNo) {
                if (flights[i].bookedSeatNum >= flights[i].seatNum) {
                    cout << "该航班已满座，无法订票！" << endl;
                    return;
                }
                flights[i].bookedSeatNum++;
                break;
            }
        }
        if (i == flightNum) {
            cout << "未找到要订票的航班！" << endl;
            return;
        }
        i = 0;
        for (; i < userNum; i++) {
            if (strcmp(users[i].name, name) == 0) {
                if (users[i].ticketNum >= MAX_TICKET_NUM) {
                    cout << "您已订满 " << MAX_TICKET_NUM << " 张票，无法再订！" << endl;
                    return;
                }
                users[i].flightNo[users[i].ticketNum] = flightNo;
                users[i].ticketNum++;
                break;
            }
        }
        if (i == userNum) {
            if (userNum >= MAX_FLIGHTS) {
                cout << "用户数已达上限，无法订票！" << endl;
                flights[i].bookedSeatNum--;
                return;
            }
            strcpy(users[userNum].name, name);
            users[userNum].flightNo[0] = flightNo;
            users[userNum].ticketNum = 1;
            userNum++;
        }
        cout << "订票成功！" << endl;
    }
    void cancelTicket() {
        char name[MAX_NAME_LEN];
        int flightNo;
        cout << "请输入您的姓名：";
        cin >> name;
        cout << "请输入要退票的航班号：";
        cin >> flightNo;
        int i = 0;
        for (; i < flightNum; i++) {
            if (flights[i].flightNo == flightNo) {
                flights[i].bookedSeatNum--;
                break;
            }
        }
        if (i == flightNum) {
            cout << "未找到要退票的航班！" << endl;
            return;
        }
        i = 0;
        for (; i < userNum; i++) {
            if (strcmp(users[i].name, name) == 0) {
                int j = 0;
                for (; j < users[i].ticketNum; j++) {
                    if (users[i].flightNo[j] == flightNo) {
                        // 将数组后面的元素向前移动
                        for (int k = j + 1; k < users[i].ticketNum; k++) {
                            users[i].flightNo[k - 1] = users[i].flightNo[k];
                        }
                        users[i].ticketNum--;
                        break;
                    }
                }
                if (j == users[i].ticketNum) {
                    cout << "您未订购该航班，无法退票！" << endl;
                    flights[i].bookedSeatNum++;
                    return;
                }
                break;
            }
        }
        if (i == userNum) {
            cout << "未找到您的订票信息，无法退票！" << endl;
            flights[i].bookedSeatNum++;
            return;
        }
        cout << "退票成功！" << endl;
    }
private:
    Flight flights[MAX_FLIGHTS]; // 航班数组
    int flightNum; // 航班数
    User users[MAX_FLIGHTS]; // 用户数组
    int userNum; // 用户数
};

// 用户类
class UserClass {
public:
    UserClass() {
        management = new Management();
    }
    ~UserClass() {
        delete management;
    }
    void displayFlights() const {
        management->displayFlights();
    }
    void bookTicket() {
        management->bookTicket();
    }
    void cancelTicket() {
        management->cancelTicket();
    }
private:
    Management *management; // 管理类指针
};

int main() {
    UserClass user;
    int choice;
    do {
        cout << "====== 民航订票系统 ======" << endl;
        cout << "1. 查询航班" << endl;
        cout << "2. 订票" << endl;
        cout << "3. 退票" << endl;
        cout << "4. 退出" << endl;
        cout << "请输入您的选择：";
        cin >> choice;
        switch (choice) {
            case 1:
                user.displayFlights();
                break;
            case 2:
                user.bookTicket();
                break;
            case 3:
                user.cancelTicket();
                break;
            case 4:
                break;
            default:
                cout << "输入有误，请重新输入！" << endl;
        }
    } while (choice != 4);
    return 0;
}

注意，这个实现仅仅是一个简单的示例，还有很多需要完善的地方，例如输入校验、异常处理、界面美化等。