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、查功能封装到该类中。要求电话号码能从磁盘读写

以下是c++实现电话薄管理程序的代码，包括Mytel类和TelManager类：

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

using namespace std;

class Mytel {
private:
    string name;
    string phone;
public:
    Mytel(string n = "", string p = "") : name(n), phone(p) {}
    string getName() { return name; }
    string getPhone() { return phone; }
    void setName(string n) { name = n; }
    void setPhone(string p) { phone = p; }
};

class TelManager {
private:
    vector<Mytel> mytels;
public:
    void readFromFile(string filename) {
        ifstream fin(filename);
        if (!fin) {
            cout << "File not found!" << endl;
            return;
        }
        mytels.clear();
        string name, phone;
        while (fin >> name >> phone) {
            mytels.push_back(Mytel(name, phone));
        }
        fin.close();
    }
    void writeToFile(string filename) {
        ofstream fout(filename);
        if (!fout) {
            cout << "File not found!" << endl;
            return;
        }
        for (int i = 0; i < mytels.size(); i++) {
            fout << mytels[i].getName() << " " << mytels[i].getPhone() << endl;
        }
        fout.close();
    }
    void add(Mytel mytel) {
        mytels.push_back(mytel);
    }
    void remove(int index) {
        if (index >= 0 && index < mytels.size()) {
            mytels.erase(mytels.begin()+index);
        }
    }
    void update(int index, Mytel mytel) {
        if (index >= 0 && index < mytels.size()) {
            mytels[index] = mytel;
        }
    }
    void search(string keyword) {
        for (int i = 0; i < mytels.size(); i++) {
            if (mytels[i].getName().find(keyword) != string::npos || mytels[i].getPhone().find(keyword) != string::npos) {
                cout << mytels[i].getName() << " " << mytels[i].getPhone() << endl;
            }
        }
    }
};

int main() {
    TelManager telManager;
    telManager.readFromFile("mytels.txt");
    while (true) {
        cout << "1. Add a phone number" << endl;
        cout << "2. Remove a phone number" << endl;
        cout << "3. Update a phone number" << endl;
        cout << "4. Search phone numbers" << endl;
        cout << "5. Exit" << endl;
        int choice;
        cin >> choice;
        if (choice == 1) {
            string name, phone;
            cout << "Enter name: ";
            cin >> name;
            cout << "Enter phone: ";
            cin >> phone;
            telManager.add(Mytel(name, phone));
            telManager.writeToFile("mytels.txt");
        } else if (choice == 2) {
            int index;
            cout << "Enter index: ";
            cin >> index;
            telManager.remove(index);
            telManager.writeToFile("mytels.txt");
        } else if (choice == 3) {
            int index;
            string name, phone;
            cout << "Enter index: ";
            cin >> index;
            cout << "Enter name: ";
            cin >> name;
            cout << "Enter phone: ";
            cin >> phone;
            telManager.update(index, Mytel(name, phone));
            telManager.writeToFile("mytels.txt");
        } else if (choice == 4) {
            string keyword;
            cout << "Enter keyword: ";
            cin >> keyword;
            telManager.search(keyword);
        } else if (choice == 5) {
            break;
        } else {
            cout << "Invalid choice!" << endl;
        }
    }
    return 0;
}

在上面的代码中，Mytel类描述单个电话号码，包括名字和电话号码两个属性。TelManager类负责管理电话号码，包括从磁盘读写电话号码、增加、删除、修改、查询电话号码等操作。电话号码可以从磁盘读写，以便程序下次运行时能够恢复之前的电话号码。

在程序运行时，用户可以选择增加、删除、修改、查询电话号码等操作，对电话号码进行管理。每次操作后，程序将电话号码写回磁盘文件中，以便下次运行时能够恢复之前的电话号码。