1_2_dataset.h

size_t CalcScore(const Problem& p, const std::vector<size_t>& order) {
  MPSolver solver("solving_all_cases",
                  MPSolver::SCIP_MIXED_INTEGER_PROGRAMMING);
  std::vector<MPVariable*> books_vars;
  std::vector<std::vector<MPVariable*>> libraries_vars;
  const double infinity = solver.infinity();
  for (size_t i = 0; i < p.books_num; ++i) {
    books_vars.push_back(solver.MakeBoolVar(absl::StrCat("x_", i)));
  }
  for (const size_t ind : order) {
    auto& back = libraries_vars.emplace_back();
    for (size_t i = 0; i < p.libraries[ind].books_indices.size(); ++i) {
      back.push_back(solver.MakeBoolVar(absl::StrCat("y_", i, ind)));
    }
  }
  size_t day = 0;
  size_t iter = 0;
  for (const size_t ind : order) {
    day += p.libraries[ind].install_time;
    MPConstraint* const libs_c = solver.MakeRowConstraint(-infinity, (p.days - day) * p.libraries[ind].day_capacity);
    for (size_t i = 0; i < p.libraries[ind].books_indices.size(); ++i) {
      libs_c->SetCoefficient(libraries_vars[iter][i], 1.0);
    }
    ++iter;
  }
  std::vector<MPConstraint*> last_c;
  for (size_t i = 0; i < p.books_num; ++i) {
    last_c.push_back(solver.MakeRowConstraint(-infinity, 0));
    last_c.back()->SetCoefficient(books_vars[i], 1.0);
  }
  iter = 0;
  for (const size_t ind : order) {
    for (size_t i = 0; i < p.libraries[ind].books_indices.size(); ++i) {
      last_c[p.libraries[ind].books_indices[i]]->SetCoefficient(libraries_vars[iter][i], -1.0);
    }
    ++iter;
  }
  MPObjective* const objective = solver.MutableObjective();
  for (size_t i = 0; i < p.books_num; ++i) {
    objective->SetCoefficient(books_vars[i], 1.0 * p.books[i]);
  }
  objective->SetMaximization();
  solver.SetTimeLimit(absl::Seconds(120));
  auto start = absl::Now();
  const MPSolver::ResultStatus result_status = solver.Solve();
  auto finish = absl::Now();
  std::cerr << "Processed " << finish - start << std::endl;
  if (result_status != MPSolver::OPTIMAL) {
    std::cerr << "The problem does not have an optimal solution!" << std::endl;
  }
  std::vector<std::vector<bool>> mask;
  iter = 0;
  for (const size_t ind : order) {
    auto& back = mask.emplace_back();
    for (size_t i = 0; i < p.libraries[ind].books_indices.size(); ++i) {
      back.push_back(libraries_vars[iter][i]->solution_value() == 1.0);
    }
    ++iter;
  }
  std::cerr << "Expected objective: " << static_cast<size_t>(objective->Value()) << std::endl;
  auto got = CalcScore(p, order, mask, print_out);
  std::cerr << "Got: " << got << std::endl;
  return got;
}