using System;

using System.Collections.Generic;

using System.Linq;                  

public class Program

{

    public static void Main()

    {

        // Leaderboard of scores for each event.

        List<PlayerLeaderboardEntry> event1 = new List<PlayerLeaderboardEntry>();

        List<PlayerLeaderboardEntry> event2 = new List<PlayerLeaderboardEntry>();

        List<PlayerLeaderboardEntry> event3 = new List<PlayerLeaderboardEntry>();

        var events = new List<List<PlayerLeaderboardEntry>>();

        // Add values to the first event leaderboard.

        event1.Add(new PlayerLeaderboardEntry("101012001", "Naught", 35000));

        event1.Add(new PlayerLeaderboardEntry("101012011", "Fred", 25000));

        event1.Add(new PlayerLeaderboardEntry("101012021", "Tom", 45000));

        event1.Add(new PlayerLeaderboardEntry("101012051", "Bob", 75000));

        event1.Add(new PlayerLeaderboardEntry("101012087", "TRUMP", 115000));

        // Add values to the first event leaderboard.

        event2.Add(new PlayerLeaderboardEntry("101012001", "Naught", 20000));

        event2.Add(new PlayerLeaderboardEntry("101012021", "Tom", 25000));

        event2.Add(new PlayerLeaderboardEntry("101012051", "Bob", 15000));

        event2.Add(new PlayerLeaderboardEntry("101012087", "TRUMP", 145000));

        event2.Add(new PlayerLeaderboardEntry("101012000", "Hillary", 100));

        // Add values to the third event leaderboard.

        event3.Add(new PlayerLeaderboardEntry("101012001", null, 45000));

        event3.Add(new PlayerLeaderboardEntry("101012002", "Ted", 45000));

        event3.Add(new PlayerLeaderboardEntry("101012003", "Person", 45000));

        event3.Add(new PlayerLeaderboardEntry("101012021", "Tom", 45000));

        event3.Add(new PlayerLeaderboardEntry("101012051", "Bob", 45000));

        event3.Add(new PlayerLeaderboardEntry("101012087", "TRUMP", 45000));

        event3.Add(new PlayerLeaderboardEntry("101012000", "Hillary", 100));

        // Build merged list

           events.Add(event1);

        events.Add(event2);

        events.Add(event3);

​

        var res = events.SelectMany(x => x).GroupBy(t => new { ID = t.player_id, Name=t.player_name })

   .Select(g => new

   {

       ID = g.Key.ID,

       Name = g.Key.Name,

       Average =  g.Sum(p => p.score) / events.Count(),

       TotalScore = g.Sum(p => p.score),

       EventCount = g.Count(),

   }).ToList();

​

        // Output Header

        Console.WriteLine("{0,16} {1,15} {2,15} {3,15} {4,15} {5,15}", "Player Name", "Event 1 Score", "Event 2 Score", "Event 3 Score", "Total Score", "Average Score");

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

        // Loop though merged list and output results

        foreach(var v in res.OrderByDescending(x=>x.Average)){

            //Console.WriteLine(event2.Where(p=>p.player_id == v.ID).Select(x=>x.score).FirstOrDefault());

            Console.WriteLine("{0,16} {1,15} {2,15} {3,15} {4,15} {5,15}", v.Name, event1.Where(p=>p.player_id == v.ID).Select(x=>x.score).FirstOrDefault() , event2.Where(p=>p.player_id == v.ID).Select(x=>x.score).FirstOrDefault(),  event3.Where(p=>p.player_id == v.ID).Select(x=>x.score).FirstOrDefault(), v.TotalScore, v.Average);

        }

    }

    public class PlayerLeaderboardEntry

    {

        public string player_id { get; set; }

        public string player_name { get; set; }

        public int score { get; set; }

​

        public PlayerLeaderboardEntry(string player_id, string player_name, int score)

        {

            this.player_id = player_id;

            this.player_name = player_name;

            this.score = score;

        }

    }

}

​