1120 Friend Numbers

 1 #include<iostream>
 2 #include<map>
 3 using namespace std;
 4 
 5 int main() {
 6     int n,cnt = 0,flag = 0;
 7     cin>>n;
 8     map<int,bool> mp;
 9     for(int i = 0; i < n; ++i) {
10         int t,sum = 0;
11         cin>>t;
12         while(t) {
13             sum += t % 10;
14             t /= 10;
15         }
16         if(mp[sum] == false) cnt++,mp[sum] = true;
17     }
18     cout<<cnt<<endl;
19     for(auto it:mp) {
20         if(flag++ != 0) printf(" ");
21         cout<<it.first;
22     }
23     return 0;
24 }