05_BookLibrary

using System;
using System.Collections.Generic;
using System.Globalization;
using System.Linq;

namespace _05_BookLibrary
{
    class Program
    {
        static void Main()
        {
            int n = int.Parse(Console.ReadLine());

            List<Book> books = new List<Book>();

            for (int i = 0; i < n; i++)
            {
                string[] tokens = Console.ReadLine().Split();

                string title = tokens[0];
                string author = tokens[1];
                string publisher = tokens[2];
                DateTime releaseDate = DateTime.ParseExact(tokens[3], "dd.MM.yyyy", CultureInfo.InvariantCulture);
                string isbn = tokens[4];
                decimal price = decimal.Parse(tokens[5]);

                Book book = new Book(title, author, publisher, releaseDate, isbn, price);

                books.Add(book);
            }

            var authors = new Dictionary<string, decimal>();

            foreach (Book book in books)
            {
                if (authors.ContainsKey(book.Author) == false)
                {
                    authors.Add(book.Author, book.Price);
                }
                else
                {
                    authors[book.Author] += book.Price;
                }
            }

            var sortedAuthors = authors
                .OrderByDescending(p => p.Value)
                .ThenBy(a => a.Key)
                .ToDictionary(d => d.Key, d => d.Value);

            foreach (var author in sortedAuthors)
            {
                Console.WriteLine($"{author.Key} -> {author.Value:f2}");
            }
        }
    }

    public class Book
    {
        public Book(string title, string author, string publisher, DateTime releaseDate, string isbn, decimal price)
        {
            Title = title;
            Author = author;
            Publisher = publisher;
            ReleaseDate = releaseDate;
            Isbn = isbn;
            Price = price;
        }

        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; }
    }
}