using System.Collections.Generic;
public static void Main()
Console.WriteLine("Hello World");
var posts = new List<Post>{
PostDate = DateTime.Now.AddMinutes(-10)
PostDate = DateTime.Now.AddMinutes(-20)
PostDate = DateTime.Now.AddMinutes(-10)
PostDate = DateTime.Now.AddMinutes(-20)
var result = from post in posts
group new { post.Category, post.PostDate, post } by new { post.Category, post.ForumName }
TopicId = resultSet.Key.Category,
ForumName = resultSet.Key.ForumName,
Replies = resultSet.Count(),
MaxPostDate = resultSet.Max(t => t.PostDate),
Post = resultSet.OrderByDescending(i=>i.PostDate).Select(i=>i).FirstOrDefault().post
result.ToList().ForEach(i=>Console.WriteLine(i));
public string Category {get;set;}
public string ForumName {get;set;}
public string Content {get;set;}
public DateTime PostDate{get;set;}