static void Main(string[] args) { Library library = new Library("Library"); int booksCount = int.Parse(Console.ReadLine()); for (int i = 0; i < booksCount; i++) { library.Books.Add(Book.Parse(Console.ReadLine())); } var result = library.Books.GroupBy(t => new { Author = t.Author }) .Select(g => new { Average = g.Sum(p => p.Price), Author = g.Key.Author }) .ToDictionary(x => x.Author, x => x.Average) .OrderByDescending(x => x.Value) .ThenBy(x => x.Key); foreach (var pair in result) { Console.WriteLine($"{pair.Key} -> {pair.Value:f}"); } }
static void Main(string[] args) { Library library = new Library("Library"); int booksCount = int.Parse(Console.ReadLine()); for (int i = 0; i < booksCount; i++) { library.Books.Add(Book.Parse(Console.ReadLine())); } DateTime desiredDate = DateTime.ParseExact(Console.ReadLine(), "dd.MM.yyyy", CultureInfo.InvariantCulture); var result = library.Books.Where(b => b.ReleaseDate > desiredDate) .OrderBy(b => b.ReleaseDate) .ThenBy(b => b.Author); foreach (var book in result) { Console.WriteLine($"{book.Title} -> {book.ReleaseDate:dd.MM.yyyy}"); } }