#include <iostream>
#include <algorithm>
using namespace std;
int main(){
    cout<<"hello ,world"<<endl;
    string username,username1,username2;
    string password,password1,password2,password3;
    cout<<"注册用户中"<<endl;
    cout<<"请输入密码(不能有字母，空格等：";
    cin>>password;
    cout<<"请再次确认您的密码";
    cin>>password2;
    if (password!=password2){
        cout<<"您输入的密码与上一次不相符，请重新输入";
    }
    if (password==password2){
            cout<<"现在请输入您的用户名：";
            cin>>username;
    }
    cout<<"注册成功了，现在让我们试着登录一下吧！"<<endl;
    cout<<"请输入用户名";
    cin>>username1;
    if (username1==username){
        cout<<"请输入密码";
        cin>>password1;
    }
    if (password1==password){
        cout<<"登录成功";
    }
    if (password1!=password&&username!=username1){
        cout<<"用户名或者密码不正确，请重新输入，或者输入1找回密码";
    }else if (password1=="1"){
        cout<<"找回密码中";
        cout<<"请输入用户名";
        cin>>username2;
        if (username2==username){
            cout<<"现在，请输入您的新密码";
            cin>>password3;
            cout<<"修改密码成功"<<endl;
            cout<<"登陆中";
            cout<<"请输入用户名";
            cin>>username1;
            if (username1==username){
                cout<<"请输入密码";
                cin>>password1;
            }
            if (username1!=username){
                cout<<"用户名不正确";
            }
            if (password1==password){
                cout<<"登录成功";
            }
            if (password1!=password){
                cout<<"您输入的密码有误，请重新输入，由于您刚刚尝试找回密码，找回密码不可用";
            }
        }
    }
    return 0;
}