// Class with the functionality required for Ü9.
class WordCounter {

    // Read file with given name.
 void readFile(String fileName);

 // Update counts per word (wordCounts below) for given string of words.
void updateWordCounts(Array<String> words);

// Sort words by counts, and return the k words with the largest counts.
Array<Pair<String,Integer>> computeFrequentWords(Integer k);

// Word counts.
Map<String, Integer> wordCounts;
}

void StlDemo::readMovieInfo(std::string fileName) {
std::ifstream file(fileName.c_str());
std::string line;
while (true) {
 std::getline(file, line);
 if (file.eof()) break;
 // Parse line into title, year, popularity.
 size_t pos1 = line.find("t");
  if (pos1 == std::string::npos) continue;
  size_t pos2 = line.find("t", pos1 + 1);
  if (pos2 == std::string::npos) continue;
  Movie movie;
  movie.title = line.substr(0, pos1);
  movie.year = atoi(line.substr(pos1 + 1, pos2 - pos1).c_str());
  movie.popularity = atoi(line.substr(pos2 + 1).c_str());
  // Insert into map.
  moviesByYear[movie.year].push_back(movie);
  // std::cout << """ << movie.title << "", "
  //   << movie.year << ", " << movie.popularity << std::endl;
 }
}

// ___________________________________________________
void StlDemo::sortByPopularity() {
 for (auto& pair : moviesByYear) {
  auto& movies = pair.second;
  std::sort(movies.begin(), movies.end(), [](const Movie& x, const Movie& y)
      { return x.popularity > y.popularity; });
  }
}