It was an ordinary grim October morning. The sky was covered by heavy gray clouds. It was a little rainy. The rain drops fell on the windows with quiet bangs. Ilya was sitting at the computer and gloomy
looking out of the window at the bleak scenery. Suddenly, a note caught his attention from the lower right corner of the screen. It said: “You have 1 unread email message(s)”. The boy braced himself for a bit of useless spam and opened the letter. But it turned
out much more interesting...
Dear Sir, You have received this message from the “Rutnok BKS” HR department!
We have received your application for a software developer and we found your CV quite interesting. We would like to suggest a simple test task to evaluate your professional skills. Your task is to implement
the register system for a forum. It must support three types of operations:
- “register username password”: to register a new user with name “username” and password “password”. If such user already exists in the database, the system should output the error message “fail: user already exists”. Otherwise, it should output message “success:
new user added”. - “login username password”: to log into the system as user “username” with password “password”. If such user does not exist, the system should output “fail: no such user”. Otherwise, if the user enters an incorrect password, the system should output “fail:
incorrect password”. Otherwise, if the user is already logged in the system at that moment, it should output “fail: already logged in”. Otherwise, it should output “success: user logged in”. - “logout username”: to log out of the system as user “username”. If such user does not exist, the system should output “fail: no such user”. Otherwise, if the user isn’t in the system at that moment, it should output “fail: already logged out”. Otherwise,
it should output “success: user logged out”.
Use this letter as a formal description of the algorithm and follow the described format of system messages. Good luck!
Ilya stopped doing anything else and started solving the test task. You can try to solve it as well!
Input
The first line contains an integer n that is the number of operations (1 ≤ n ≤ 100). Each of the next n lines contains a single query in the format given above. We can assume
that “username” and “password” are non-empty strings with length of up to 30 characters. All characters in these strings have codes from 33 to 126.
Output
For each operation, print the message on a single line in the format given above. Be sure to put spaces and punctuation marks in the right places in the messages.
Sample
| input | output |
|---|---|
6 register vasya 12345 login vasya 1234 login vasya 12345 login anakin C-3PO logout vasya logout vasya |
success: new user added fail: incorrect password success: user logged in fail: no such user success: user logged out fail: already logged out |
实现一个登陆系统。
思路：
1 使用map，在map中的就是已经注册的了
2 使用数据结构保存用户名，是否登陆和密码
3 使用if else判断处理第一个字符串-命令
类似很多人都写的什么图书馆管理系统，什么信息系统之类的登陆控制管理，都是很简单的东西，一步一步写就不会错了，完成速度相当于打字速度。
#include <string>
#include <vector>
#include <cmath>
#include <algorithm>
#include <iostream>
#include <unordered_map>
#include <unordered_set>
using namespace std;
namespace
{
struct States
{
bool logined;
string name;
string pw;
States(string n="", string p="", bool l = false):
name(n), pw(p), logined(l){}
};
}
void TestTask2002()
{
int opTimes = 0;
cin>>opTimes;
unordered_map<string, States> umSS;
string command, name, pw;
while (opTimes--)
{
cin>>command>>name;
if ("register" == command)
{
cin>>pw;//logout不用pw的
if (umSS.count(name)) cout<<"fail: user already exists\n";
else
{
States st(name, pw);
umSS[name] = st;
cout<<"success: new user added\n";
}
}
else if ("login" == command)
{
cin>>pw;
if (!umSS.count(name)) cout<<"fail: no such user\n";
else if (pw != umSS[name].pw) cout<<"fail: incorrect password\n";
else if (umSS[name].logined) cout<<"fail: already logged in\n";
else
{
cout<<"success: user logged in\n";
umSS[name].logined = true;
}
}
else if ("logout" == command)
{
if (!umSS.count(name)) cout<<"fail: no such user\n";
else if (!(umSS[name].logined)) cout<<"fail: already logged out\n";
else
{
cout<<"success: user logged out\n";
umSS[name].logined = false;
}
}
}
}