如果你密码输入错误，四次后转入验证码服务，验证码通过了，可以重新设置密码

思路：一个类，有变量用户名，密码，和验证码，有一些函数，读取用户名密码 验证验证码

验证码发送可以是虚拟的，语句提示即可，程序通过也可以是虚拟的，语句提示即可

  1. 这时按题目要求做的，基本封装成函数了，只想要读取变量的三个函数，和修改密码的函数，可以把friend三个函数的逻辑放到main里面，不作为函数处理（看第二个代码）

#include <iostream>
#include <cstring>

using namespace std;

class User
{
    public:
        User(string un, string pw, int vs) : username(un), password(pw), verifysum(vs) {}
        ~User() {cout << "Exit~" << endl;}
        string  GetUserName();
        string  GetPassWord();
        int     GetVerifySum();
        void    SetPassword(string pw);
        friend bool LoginByPassWord(User& u, string un, string pw);
        friend bool LoginByVerifySum(User& u, string un, int vs);
        friend void ChangePassWord(User& u, string pw);

    private:
        string username;
        string password;
        int verifysum;
};

string  User::GetUserName()
{
    return username;
}

string  User::GetPassWord()
{
    return password;
}

int     User::GetVerifySum()
{
    return verifysum;
}

void    User::SetPassword(string pw)
{
    password = pw;
}

bool    LoginByPassWord(User& u, string un, string pw)
{
    if (u.GetUserName() == un && u.GetPassWord() == pw)
    {
        cout << "Login success." << endl;
        return true;
    }
    return false;
}

bool    LoginByVerifySum(User& u, string un, int vs)
{
    if (u.GetUserName() == un && u.GetVerifySum() == vs)
    {
        cout << "Login success." << endl;
        return true;
    }
    return false;
}

void    ChangePassWord(User& u, string pw)
{
    u.SetPassword(pw);
    cout << "Change password success." << endl;
}

int main()
{
    User u("admin", "admin", 520);      //初始化对象

    int first = 4;
    string n_un, n_pw;
    int n_vs;
    while (first--)
    {
        cout << "Please input username and paddword: ";
        cin >> n_un >> n_pw;
        if (LoginByPassWord(u, n_un, n_pw))
        {
            return 0;
        }
        cout << "Login failed,  remaining times: " << first << endl;
    }

    cout << "Please use the verification code to verify the login." << endl;
    cout << "Please input verifysum: ";
    cin >> n_vs;
    if (LoginByVerifySum(u, n_un, n_vs))
    {
        cout << "Please change your password: ";
        cin >> n_pw;
        ChangePassWord(u, n_pw);
    }
    else
    {
        cout << "VerifySum is Error." << endl;
    }
    return 0;
}
  1. 只有题目要求得函数

#include <iostream>
#include <cstring>

using namespace std;

class User
{
    public:
        User(string un, string pw, int vs) : username(un), password(pw), verifysum(vs) {}
        ~User() {cout << "Exit~" << endl;}
        string  GetUserName();
        string  GetPassWord();
        int     GetVerifySum();
        void    SetPassword(string pw);

    private:
        string username;
        string password;
        int verifysum;
};

string  User::GetUserName()
{
    return username;
}

string  User::GetPassWord()
{
    return password;
}

int     User::GetVerifySum()
{
    return verifysum;
}

void    User::SetPassword(string pw)
{
    password = pw;
}

int main()
{
    User u("admin", "admin", 520);      //初始化对象

    int first = 4;
    string n_un, n_pw;
    int n_vs;
    while (first--)
    {
        cout << "Please input username and paddword: ";
        cin >> n_un >> n_pw;
        if (u.GetUserName() == n_un && u.GetPassWord() == n_pw)
        {
            cout << "Login success." << endl;
            return 0;
        }
        cout << "Login failed,  remaining times: " << first << endl;
    }

    cout << "Please use the verification code to verify the login." << endl;
    cout << "Please input verifysum: ";
    cin >> n_vs;
    if (u.GetUserName() == n_un && u.GetVerifySum() == n_vs)
    {
        cout << "Login success." << endl;
        cout << "Please change your password: ";
        cin >> n_pw;
        u.SetPassword(n_pw);
    }
    else
    {
        cout << "VerifySum is Error." << endl;
    }
    return 0;
}

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