Update all new Tasks

Task/Hash-join/C-sharp/hash-join.cs

@@ -0,0 +1,100 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace HashJoin
+{
+    public class AgeName
+    {
+        public AgeName(byte age, string name)
+        {
+            Age = age;
+            Name = name;
+        }
+        public byte Age { get; private set; }
+        public string Name { get; private set; }
+    }
+
+    public class NameNemesis
+    {
+        public NameNemesis(string name, string nemesis)
+        {
+            Name = name;
+            Nemesis = nemesis;
+        }
+        public string Name { get; private set; }
+        public string Nemesis { get; private set; }
+    }
+
+    public class DataContext
+    {
+        public DataContext()
+        {
+            AgeName = new List<AgeName>();
+            NameNemesis = new List<NameNemesis>();
+        }
+        public List<AgeName> AgeName { get; set; }
+        public List<NameNemesis> NameNemesis { get; set; }
+    }
+
+    public class AgeNameNemesis
+    {
+        public AgeNameNemesis(byte age, string name, string nemesis)
+        {
+            Age = age;
+            Name = name;
+            Nemesis = nemesis;
+        }
+        public byte Age { get; private set; }
+        public string Name { get; private set; }
+        public string Nemesis { get; private set; }
+    }
+
+    class Program
+    {
+        public static void Main()
+        {
+            var data = GetData();
+            var result = ExecuteHashJoin(data);
+            WriteResultToConsole(result);
+        }
+
+        private static void WriteResultToConsole(List<AgeNameNemesis> result)
+        {
+            result.ForEach(ageNameNemesis => Console.WriteLine("Age: {0}, Name: {1}, Nemesis: {2}",
+                ageNameNemesis.Age, ageNameNemesis.Name, ageNameNemesis.Nemesis));
+        }
+
+        private static List<AgeNameNemesis> ExecuteHashJoin(DataContext data)
+        {
+            return (data.AgeName.Join(data.NameNemesis,
+                ageName => ageName.Name, nameNemesis => nameNemesis.Name,
+                (ageName, nameNemesis) => new AgeNameNemesis(ageName.Age, ageName.Name, nameNemesis.Nemesis)))
+                .ToList();
+        }
+
+        private static DataContext GetData()
+        {
+            var context = new DataContext();
+
+            context.AgeName.AddRange(new [] {
+                    new AgeName(27, "Jonah"),
+                    new AgeName(18, "Alan"),
+                    new AgeName(28, "Glory"),
+                    new AgeName(18, "Popeye"),
+                    new AgeName(28, "Alan")
+                });
+
+            context.NameNemesis.AddRange(new[]
+            {
+                new NameNemesis("Jonah", "Whales"),
+                new NameNemesis("Jonah", "Spiders"),
+                new NameNemesis("Alan", "Ghosts"),
+                new NameNemesis("Alan", "Zombies"),
+                new NameNemesis("Glory", "Buffy")
+            });
+
+            return context;
+        }
+    }
+}