hard_prime

#include <bits/stdc++.h>
using namespace std;
ifstream fin("hard_prime.in");
ofstream fout("hard_prime.out");
bool isPrime(int nr)
{
    if (nr <= 1)
        return false;
    if (nr <= 3)
        return true;
    if (nr % 2 == 0 || nr % 3 == 0)
        return false;
    for (int i = 5; i * i <= nr; i = i + 6)
        if (nr % i == 0 || nr % (i + 2) == 0)
            return false;
    return true;
}

int main()
{
    int n, nr;
    fin>>n;
    vector <int>a;
    vector<int>::iterator ip;
    for(int i=0; i<=n; i++)
    {
        fin>>nr;
        if(nr==2)
            a.push_back(nr);
        else if(nr%2)
            if(isPrime(nr))
                a.push_back(nr);
    }
    sort(a.begin(), a.end());
    ip = unique(a.begin(), a.begin() + a.size());
    a.resize(distance(a.begin(), ip));
    for(ip = a.begin(); ip != a.end(); ++ip)
        fout << *ip << " ";
    return 0;
}