Қайдан Kazakhstan Competitive Programming Championship #2

Ақпарат

The best thing ever: template <typename Iter, typename=decltype(declval<Iter>().begin()), typename=enable_if_t<!is_convertible_v<Iter, string>>> ostream& operator<<(ostream& out, const Iter& x){ for (const auto& i : x) out << i << ' '; return out;}