public static IEnumerable <Book> GetLinqAndLeapYearBooks()
{
IEnumerable <Book> books = Initializer.GetNewLibrary();
IEnumerable <Book> requiredBooks = books.Where(book => book.Name.Contains("LINQ") && DateTime.IsLeapYear(book.Year));
return(requiredBooks);
}
public static Dictionary <string, int> GetPairsAuthorAndBookCount()
{
IEnumerable <Book> books = Initializer.GetNewLibrary();
var result = books.Select(book => book.Author).GroupBy(
author => author,
(key, value) => new
{
Author = key,
BooksCount = value.Count()
}
).ToDictionary(x => x.Author, x => x.BooksCount);
return(result);
}