using System;

using System.Collections.Generic;

using System.Linq;

public class Program

{   

    class A

    {

        public int Index { get; set; }

        public bool State { get; set; }

    }

         public static void Main()

         {

             List<A> list1 = new List<A>()

             {

             new A(){ Index = 1, State = false },

             new A(){ Index = 2, State = false },

             new A(){ Index = 3, State = true },

             new A(){ Index = 4, State = false },

             new A(){ Index = 5, State = false },

         };

             List<A> list2 = new List<A>() 

             {

             new A(){ Index = 1, State = false },

             new A(){ Index = 2, State = true },

             new A(){ Index = 3, State = true },

             new A(){ Index = 4, State = false },

             new A(){ Index = 5, State = false },

             new A(){ Index = 6, State = true },

             new A(){ Index = 7, State = false },

         };

             var list = list1.Concat(list2);

             var re = from a in list

                      group a by a.Index into g

                      select new

                      {

                          Key = g.Key,

                          Value = g.Where(x => x.State == true).Count() > 0 ? true : false

                      };

             Dictionary<int, bool> dict1 = re.ToDictionary(x => x.Key, y => y.Value);

                foreach (var item in dict1)

        {

            Console.WriteLine("{0} {1}", item.Key, item.Value);

        }

         }

​

}