RsVBmmfY

1#include <iostream>
2#include <vector>
3#include <list>
4#include <utility>
5#include <algorithm>
6#include <cctype>
7using namespace std;
8
9typedef pair <string,string> email;
10
11// разделение на имя пользователя и домен
12email split(string in){
13    int loc = in.find('@');
14    email res;
15    res.first = in.substr(0, loc);
16    transform(res.first.begin(), res.first.end(), res.first.begin(),
17    [](unsigned char c){ return std::tolower(c); });
18    res.second = in.substr(loc+1);
19    transform(res.second.begin(), res.second.end(), res.second.begin(),
20    [](unsigned char c){ return std::tolower(c); });
21    return res;
22}
23
24
25email clear(email in){
26    // удаление точек
27    for(string::iterator it=in.first.begin(); it!=in.first.end(); ++it){
28        int dot_pos = in.first.find('.');
29        //cout << dot_pos << "\t" << in.first <<endl;
30        if(dot_pos > 0) in.first.erase(in.first.begin() + dot_pos);
31    }
32    // удаление после первого плюса
33    int plus_pos = in.first.find('+');
34    in.first = in.first.substr(0, plus_pos);
35    //cout << plus_pos << "\t" << in.first << endl;
36    return in;
37}
38
39
40int main(){
41    int count;
42    cin >> count;
43    vector<string> in(count);
44    vector<email> out(count);
45    vector<list<string>> res;
46
47    for(int i = 0; i < count; ++i){
48        string s;
49        cin >> s;
50        in[i] = s;
51        email cur = split(s);
52        if(cur.second == "gmail.com") cur = clear(cur);
53        out[i] = cur;
54    }
55    
56    for(int i = 0; i < count; ++i){
57        list<string> r;
58        if(!out[i].first.empty()) r.push_back(in[i]);
59        for(int j = i + 1; j < count; ++j){
60            if(!out[j].first.empty() && out[j] == out[i]) {
61                r.push_back(in[j]);
62                out[j] = {};
63            }
64        }
65        if(!r.empty()) res.push_back(r);
66    }
67
68    cout << res.size() << endl;
69    for(auto a : res){
70        cout << a.size() << " ";
71        for(auto el : a) cout << el << "\t";
72        cout << endl;
73    }
74
75    return 0;
76}