05.BookLibrary

using System;
using System.Collections.Generic;
using System.Globalization;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Book_Library_Q
{
    class Book
    {
        public string Title { get; set; }
        public string Author { get; set; }
        public string Publisher { get; set; }
        public DateTime ReleaseDate { get; set; }
        public string ISBN { get; set; }
        public decimal Price { get; set; }
    }
    class Library
    {
        public string Name { get; set; }
        public List<Book> Books { get; set; }
    }
    class Program
    {
        static void Main()
        {
            Dictionary<string, decimal> output = new Dictionary<string, decimal>();

            int num = int.Parse(Console.ReadLine());
            Library library = new Library();
            ImportBooks(library, num);


             foreach (string author in library.Books.Select(x => x.Author).Distinct())
             {
                 output.Add(author, library.Books.Where(x => x.Author == author)
                                               .Select(x => x.Price)
                                               .Sum());
             }

             foreach (var pair in output.OrderByDescending(x => x.Value).ThenBy(x => x.Key))
                 Console.WriteLine("{0} -> {1:f2}", pair.Key, pair.Value);

        }

        static void ImportBooks(Library library, int num)
        {
            for (int i = 0; i < num; i++)
            {
                library.Books = new List<Book>(); // Initialize the List before using it
                string[] input = Console.ReadLine().Split();
                library.Books.Add(new Book()
                {
                    Title = input[0],
                    Author = input[1],
                    Publisher = input[2],
                    ReleaseDate = DateTime.ParseExact(input[3], "dd.MM.yyyy", CultureInfo.InvariantCulture),
                    ISBN = input[4],
                    Price = decimal.Parse(input[5])
                });
            }
        }
    }
}