hXYwcLPw

1using System;
2using System.Collections.Generic;
3using System.Linq;
4using System.Text;
5using System.Text.RegularExpressions;
6using System.Threading.Tasks;
7
8namespace ConsoleApp2
9{
10    class Program
11    {
12        static void Main(string[] args)
13        {
14            if (int.TryParse(Console.ReadLine(), out int emailsCount))
15            {
16                if (emailsCount >= 1 && emailsCount <= 20000)
17                {
18                    string[] emails = new string[emailsCount];
19                    for (int i = 0; i < emailsCount; i++)
20                    {
21                        emails[i] = Console.ReadLine();
22
23                        Regex loginEx = new Regex(@"^[A-z][A-z\.\+0-9]*@(([A-z]*)(\.)([A-z]+))+$");
24                        if (!loginEx.IsMatch(emails[i]))
25                        {
26                            Console.WriteLine("Адрес введен неверно");
27                            i--;
28                            continue;
29                        }
30                    }
31
32                    // заполнили адресами
33
34                    Dictionary<string, List<string>> equalGroups = new Dictionary<string, List<string>>();
35
36                    for (int i = 0; i < emailsCount; i++)
37                    {
38                        string login = emails[i].Split('@')[0];
39                        string loginView = login.ToLower();
40                        string domain = emails[i].Split('@')[1];
41
42                        if (domain.ToLower() == "gmail.com" )
43                        {
44                            loginView = loginView.Replace(".", "");
45                            loginView = loginView.Split('+')[0];
46                        }
47
48                        string fullName = loginView + "@" + domain.ToLower();
49
50                        if (equalGroups.ContainsKey(fullName))
51                        {
52                            equalGroups[fullName].Add(emails[i]);
53                        }
54                        else
55                        {
56                            equalGroups.Add(fullName, new List<string>() { emails[i] });
57                        }
58                    }
59
60                    Console.WriteLine(equalGroups.Count);
61                    for (int i = 0; i < equalGroups.Count; i++)
62                    {
63                        Console.Write(equalGroups.ElementAt(i).Value.Count + " ");
64
65                        string res = "";
66                        for (int j = 0; j < equalGroups.ElementAt(i).Value.Count; j++)
67                        {
68                            res += equalGroups.ElementAt(i).Value[j] + " ";
69                        }
70                        res.Trim();
71                        Console.WriteLine(res);
72                    }
73                }
74            }
75        }
76    }
77}