1120. Friend Numbers (20)

#include<iostream>
#include<vector>
#include<string>
#include<set>
using namespace std;
int main()
{
int a[40] = {};
set<int> re;
int N;
cin >> N;
while (N--)
{
string tmp;
cin >> tmp;
int sum=0;
for (auto x : tmp)
sum += x - '0';
re.insert(sum);
}
cout << re.size() << endl;
int cnt=0;
for (auto x : re)
if (!cnt++) printf("%d", x);
else printf(" %d", x);
cout << endl;

}