1064. 朋友数(20) PAT 乙级

#include<iostream>
#include<set>
using namespace std;

int sum(int n){
int count=0;
while(n>0){

count+=n%10;
n/=10;
}
return count;
}

int main(){
int N;
int num;
set<int> s;
cin>>N;
for(int i=0;i<N;i++){
cin>>num;
s.insert(sum(num));
}
cout<<s.size()<<endl;
set<int >::iterator it,it1;
for(it1=it=s.begin();it!=s.end();it++){
cout<<*it;
it1++;

if((it1)!=s.end())cout<<" ";
}
//cout<<"aa";
}