使用c++以及链表的结构写一个点餐系统，尽可能详细功能丰富

好的，我可以为您提供一些 C++ 链表点餐系统的实现思路和代码示例。这个系统可以实现以下功能：

1. 菜单的展示
2. 点餐和加菜
3. 订单的展示和总价的计算
4. 取消订单和删除菜品
5. 导出订单到文件

接下来，让我们来一步步实现这些功能。

首先，我们需要定义一个菜单类（Menu），用于存储所有的菜品信息。每个菜品包含名字、价格和描述等信息。我们可以使用链表来存储所有的菜品信息。

#include <iostream>
#include <fstream>
#include <string>
using namespace std;

// 定义菜品结构体
struct MenuItem {
    string name;
    string description;
    double price;
    MenuItem* next;
};

class Menu {
public:
    Menu() {
        head = NULL;
        size = 0;
    }
    
    // 添加菜品
    void addMenuItem(string name, string description, double price) {
        MenuItem* item = new MenuItem;
        item->name = name;
        item->description = description;
        item->price = price;
        item->next = head;
        head = item;
        size++;
    }
    
    // 展示菜单
    void showMenu() {
        MenuItem* current = head;
        while (current != NULL) {
            cout << current->name << " - " << current->description << " - " << current->price << endl;
            current = current->next;
        }
    }
    
    // 导出菜单到文件
    void exportMenuToFile(string fileName) {
        ofstream outFile;
        outFile.open(fileName);
        MenuItem* current = head;
        while (current != NULL) {
            outFile << current->name << "," << current->description << "," << current->price << endl;
            current = current->next;
        }
        outFile.close();
    }
    
    // 从文件导入菜单
    void importMenuFromFile(string fileName) {
        ifstream inFile;
        inFile.open(fileName);
        string line;
        while (getline(inFile, line)) {
            string name, description;
            double price;
            int pos1 = line.find(",");
            name = line.substr(0, pos1);
            int pos2 = line.find(",", pos1 + 1);
            description = line.substr(pos1 + 1, pos2 - pos1 - 1);
            price = stod(line.substr(pos2 + 1));
            addMenuItem(name, description, price);
        }
        inFile.close();
    }
    
    // 根据菜品名查找菜品
    MenuItem* findMenuItem(string name) {
        MenuItem* current = head;
        while (current != NULL) {
            if (current->name == name) {
                return current;
            }
            current = current->next;
        }
        return NULL;
    }
    
private:
    MenuItem* head;
    int size;
};

接下来，我们需要定义一个订单类（Order），用于存储所有的订单信息。订单包含订单号、时间、菜品列表等信息。同样，我们可以使用链表来存储所有的订单信息。

#include <iostream>
#include <string>
#include <ctime>
using namespace std;

// 定义订单结构体
struct OrderItem {
    string name;
    double price;
    OrderItem* next;
};

struct Order {
    int id;
    time_t time;
    OrderItem* itemList;
    Order* next;
};

class OrderList {
public:
    OrderList() {
        head = NULL;
        size = 0;
    }
    
    // 添加订单
    void addOrder(Order* order) {
        order->id = size + 1;
        order->time = time(0);
        order->next = head;
        head = order;
        size++;
    }
    
    // 展示订单
    void showOrder(int id) {
        Order* current = head;
        while (current != NULL) {
            if (current->id == id) {
                cout << "订单号：" << current->id << endl;
                cout << "时间：" << ctime(&current->time);
                OrderItem* item = current->itemList;
                double totalPrice = 0;
                while (item != NULL) {
                    cout << item->name << " - " << item->price << endl;
                    totalPrice += item->price;
                    item = item->next;
                }
                cout << "总价：" << totalPrice << endl;
                return;
            }
            current = current->next;
        }
        cout << "没有找到该订单！" << endl;
    }
    
    // 删除订单
    void deleteOrder(int id) {
        if (head == NULL) {
            cout << "订单列表为空，无法删除订单！" << endl;
            return;
        }
        if (head->id == id) {
            Order* temp = head;
            head = head->next;
            delete temp;
            size--;
            cout << "订单删除成功！" << endl;
            return;
        }
        Order* current = head;
        while (current->next != NULL) {
            if (current->next->id == id) {
                Order* temp = current->next;
                current->next = temp->next;
                delete temp;
                size--;
                cout << "订单删除成功！" << endl;
                return;
            }
            current = current->next;
        }
        cout << "没有找到该订单！" << endl;
    }
    
    // 导出订单到文件
    void exportOrderToFile(string fileName) {
        ofstream outFile;
        outFile.open(fileName);
        Order* current = head;
        while (current != NULL) {
            outFile << current->id << "," << ctime(&current->time);
            OrderItem* item = current->itemList;
            while (item != NULL) {
                outFile << item->name << "," << item->price << ",";
                item = item->next;
            }
            outFile << endl;
            current = current->next;
        }
        outFile.close();
    }
    
    // 从文件导入订单
    void importOrderFromFile(string fileName, Menu* menu) {
        ifstream inFile;
        inFile.open(fileName);
        string line;
        while (getline(inFile, line)) {
            Order* order = new Order;
            int pos1 = line.find(",");
            order->id = stoi(line.substr(0, pos1));
            int pos2 = line.find(",", pos1 + 1);
            order->time = stol(line.substr(pos1 + 1, pos2 - pos1 - 1));
            OrderItem* itemList = NULL;
            int pos = pos2 + 1;
            while (pos < line.length()) {
                pos1 = line.find(",", pos);
                string name = line.substr(pos, pos1 - pos);
                pos2 = line.find(",", pos1 + 1);
                double price = stod(line.substr(pos1 + 1, pos2 - pos1 - 1));
                MenuItem* menuItem = menu->findMenuItem(name);
                if (menuItem == NULL) {
                    cout << "菜单中没有该菜品：" << name << endl;
                } else {
                    OrderItem* item = new OrderItem;
                    item->name = name;
                    item->price = menuItem->price;
                    item->next = itemList;
                    itemList = item;
                }
                pos = pos2 + 1;
            }
            order->itemList = itemList;
            addOrder(order);
        }
        inFile.close();
    }
    
    // 点餐
    void order(Menu* menu) {
        Order* order = new Order;
        order->itemList = NULL;
        string name;
        while (true) {
            cout << "请输入您要点的菜品名（输入 exit 结束点餐）：" << endl;
            cin >> name;
            if (name == "exit") {
                break;
            }
            MenuItem* menuItem = menu->findMenuItem(name);
            if (menuItem == NULL) {
                cout << "菜单中没有该菜品：" << name << endl;
            } else {
                OrderItem* item = new OrderItem;
                item->name = name;
                item->price = menuItem->price;
                item->next = order->itemList;
                order->itemList = item;
            }
        }
        if (order->itemList == NULL) {
            cout << "您没有选择任何菜品！" << endl;
            delete order;
        } else {
            addOrder(order);
            cout << "订单添加成功！" << endl;
        }
    }
    
private:
    Order* head;
    int size;
};

最后，我们需要一个主函数来调用上面的类和函数，实现点餐系统的整体功能。

int main() {
    Menu menu;
    menu.importMenuFromFile("menu.txt");
    menu.showMenu();
    OrderList orderList;
    orderList.importOrderFromFile("orders.txt", &menu);
    while (true) {
        cout << "请输入选项编号：" << endl;
        cout << "1. 点餐" << endl;
        cout << "2. 查看订单" << endl;
        cout << "3. 删除订单" << endl;
        cout << "4. 导出订单到文件" << endl;
        cout << "5. 退出系统" << endl;
        int option;
        cin >> option;
        switch (option) {
            case 1:
                orderList.order(&menu);
                break;
            case 2:
                int id;
                cout << "请输入要查看的订单号：" << endl;
                cin >> id;
                orderList.showOrder(id);
                break;
            case 3:
                cout << "请输入要删除的订单号：" << endl;
                cin >> id;
                orderList.deleteOrder(id);
                break;
            case 4:
                orderList.exportOrderToFile("orders.txt");
                break;
            case 5:
                menu.exportMenuToFile("menu.txt");
                cout << "谢谢使用！" << endl;
                return 0;
            default:
                cout << "无效的选项，请重新输入！" << endl;
                break;
        }
    }
}

以上是一个简单的 C++ 链表点餐系统实现思路和代码示例，您可以根据您的需求进行修改和完善。