c++实现电话薄管理程序，Mytel类描述单个电话号码，TelManager类负责管理电话号码，把增删改查功能封装到该类，要求电话号码能从磁盘读写

以下是一个简单的实现：

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

using namespace std;

class Mytel {
private:
    string name;
    string number;
public:
    Mytel(string n = "", string num = ""): name(n), number(num) {}
    string getName() const { return name; }
    string getNumber() const { return number; }
    void setName(string n) { name = n; }
    void setNumber(string num) { number = num; }
    void print() const { cout << name << ": " << number << endl; }
};

class TelManager {
private:
    vector<Mytel> phonebook;
    string filename;
public:
    TelManager(string fname) : filename(fname) {}
    void load() {
        ifstream fin(filename);
        if (!fin.is_open()) {
            cout << "Error opening file " << filename << endl;
            return;
        }
        string name, number;
        while (fin >> name >> number) {
            Mytel entry(name, number);
            phonebook.push_back(entry);
        }
        fin.close();
    }
    void save() const {
        ofstream fout(filename);
        if (!fout.is_open()) {
            cout << "Error opening file " << filename << endl;
            return;
        }
        for (const auto& entry : phonebook) {
            fout << entry.getName() << " " << entry.getNumber() << endl;
        }
        fout.close();
    }
    void addEntry(const Mytel& entry) {
        phonebook.push_back(entry);
    }
    void removeEntry(const Mytel& entry) {
        for (auto it = phonebook.begin(); it != phonebook.end(); it++) {
            if (it->getName() == entry.getName() && it->getNumber() == entry.getNumber()) {
                phonebook.erase(it);
                break;
            }
        }
    }
    void updateEntry(const Mytel& oldEntry, const Mytel& newEntry) {
        for (auto& entry : phonebook) {
            if (entry.getName() == oldEntry.getName() && entry.getNumber() == oldEntry.getNumber()) {
                entry = newEntry;
                break;
            }
        }
    }
    Mytel findEntry(const string& name) const {
        for (const auto& entry : phonebook) {
            if (entry.getName() == name) {
                return entry;
            }
        }
        return Mytel("", "");
    }
    void printAllEntries() const {
        for (const auto& entry : phonebook) {
            entry.print();
        }
    }
};

int main() {
    TelManager manager("phonebook.txt");
    manager.load();

    cout << "Select option:" << endl;
    cout << "1. Add entry" << endl;
    cout << "2. Remove entry" << endl;
    cout << "3. Update entry" << endl;
    cout << "4. Find entry" << endl;
    cout << "5. Print all entries" << endl;
    cout << "6. Exit" << endl;

    int option;
    do {
        cout << "Option: ";
        cin >> option;
        switch (option) {
            case 1: {
                string name, number;
                cout << "Enter name: ";
                cin >> name;
                cout << "Enter number: ";
                cin >> number;
                Mytel entry(name, number);
                manager.addEntry(entry);
                manager.save();
                break;
            }
            case 2: {
                string name, number;
                cout << "Enter name: ";
                cin >> name;
                cout << "Enter number: ";
                cin >> number;
                Mytel entry(name, number);
                manager.removeEntry(entry);
                manager.save();
                break;
            }
            case 3: {
                string oldName, oldNumber, newName, newNumber;
                cout << "Enter old name: ";
                cin >> oldName;
                cout << "Enter old number: ";
                cin >> oldNumber;
                Mytel oldEntry(oldName, oldNumber);
                cout << "Enter new name: ";
                cin >> newName;
                cout << "Enter new number: ";
                cin >> newNumber;
                Mytel newEntry(newName, newNumber);
                manager.updateEntry(oldEntry, newEntry);
                manager.save();
                break;
            }
            case 4: {
                string name;
                cout << "Enter name: ";
                cin >> name;
                Mytel entry = manager.findEntry(name);
                if (entry.getName() != "") {
                    entry.print();
                } else {
                    cout << "Entry not found" << endl;
                }
                break;
            }
            case 5: {
                manager.printAllEntries();
                break;
            }
            case 6: {
                cout << "Exiting..." << endl;
                break;
            }
            default: {
                cout << "Invalid option" << endl;
            }
        }
    } while (option != 6);

    return 0;
}

在这个实现中，`Mytel` 类描述单个电话号码，有一个姓名和一个电话号码。`TelManager` 类负责管理电话号码，有一个 `vector` 存储所有电话号码，以及一个文件名用于读写电话号码。`load` 和 `save` 函数分别从文件中读取和写入电话号码，`addEntry`、`removeEntry`、`updateEntry` 和 `findEntry` 函数分别实现增加、删除、更新和查找电话号码的功能，`printAllEntries` 函数打印所有电话号码。在 `main` 函数中，程序通过一个循环读取用户选择的操作，然后调用相应的函数实现该操作。每次操作后，程序都会将电话号码保存到文件中。