using System;

using System.Collections.Generic;

using System.Linq;

public class Program

{

    public static void Main()

    {

         List<BrowserInfo> browesers = new List<BrowserInfo>

            {

                new BrowserInfo { UserID = 1, Browser = "Chrome-32.0"},

                new BrowserInfo { UserID = 1, Browser = "Chrome-30.0"},

                new BrowserInfo { UserID = 1, Browser = "Chrome-33.0"},

                new BrowserInfo { UserID = 1, Browser = "Firefox-20.0"},

                new BrowserInfo { UserID = 1, Browser = "Firefox-26.0"},

                new BrowserInfo { UserID = 1, Browser = "Safari"},

                new BrowserInfo { UserID = 1, Browser = "IE 9"},

                new BrowserInfo { UserID = 1, Browser = "IE 10"},

                new BrowserInfo { UserID = 2, Browser = "Chrome-31.0"},

                new BrowserInfo { UserID = 2, Browser = "Chrome-32.0"},

                new BrowserInfo { UserID = 2, Browser = "IE 10"},

                new BrowserInfo { UserID = 2, Browser = "Firefox-22.0"},

                new BrowserInfo { UserID = 2, Browser = "Firefox-20.0"}

            };

​

​

            var query = from browser in browesers

                        group browser by browser.UserID into UserGroup

                        from countGroup in

                            (from brow in UserGroup

                             group brow by new

                                 {

                                     Chrome = brow.Browser.Contains("Chrome"),

                                     Firefox = brow.Browser.Contains("Firefox"),

                                     IE = brow.Browser.Contains("IE")

                                 } into g

                                     select new

                                     {

                                         ChromeCount = g.Key.Chrome ? g.Count() : 0,

                                         FirefoxCount = g.Key.Firefox ? g.Count() : 0,

                                         IECount = g.Key.IE ? g.Count() : 0,

                                         OthersCount = (!g.Key.Chrome && !g.Key.Firefox && !g.Key.IE) ? g.Count() : 0

                                     }

                                 )

                        group countGroup by UserGroup.Key;

​

​

​

​

​

            Console.WriteLine("UserId | Chrome | Firefox | IE | Others");

            Console.WriteLine("----------------------------------------");

            foreach(var users in query)

            {

                Console.WriteLine("{0} | {1} | {2} | {3} | {4} ",

                                users.Key, users.Where(x => x.ChromeCount != 0).Select(x => x.ChromeCount).FirstOrDefault(),

                                users.Where(x => x.FirefoxCount != 0).Select(x => x.FirefoxCount).FirstOrDefault(),

                                users.Where(x => x.IECount != 0).Select(x => x.IECount).FirstOrDefault(),

                                users.Where(x => x.OthersCount != 0).Select(x => x.OthersCount).FirstOrDefault()

                        );

            }

​

    }

}

​

 public class BrowserInfo

    {

        public int UserID { get; set; }

        public string Browser { get; set; }

    }