using System;

using System.Linq;

using System.Collections.Generic;

using Newtonsoft.Json;

​

public class Program

{

    public static void Main()

    {

        var strings = new List<string>{

            "example.string.1", 

            "example.string.2", 

            "example.anotherstring.1", 

            "example.anotherstring.2", 

        };

        var result = strings.Aggregate(new Dictionary<string, Object>(), (acc, s) =>

        {

            Dictionary<string, Object> previousLevel = null;

            Dictionary<string, Object> nextLevel = acc;

            string previousSegment = null;

            foreach (string nextSegment in s.Split('.'))

            {

                short temp;

                if (Int16.TryParse(nextSegment, out temp))

                // process the final integer

                {

                    if (previousLevel[previousSegment] is Dictionary<string, Object>)

                    {

                        previousLevel[previousSegment] = new List<string>();

                    }

​

                    var list = previousLevel[previousSegment] as List<string>;

                    list.Add(nextSegment);

                }

                else

                // process each string

                {

                    if (!nextLevel.ContainsKey(nextSegment))

                    {

                        var child = new Dictionary<string, Object>();

                        nextLevel.Add(nextSegment, child);

                    }

​

                    previousSegment = nextSegment;

                    previousLevel = nextLevel;

                    nextLevel = nextLevel[nextSegment] as Dictionary<string, Object>;

                }

            }

​

            return acc;

        });

        var json = JsonConvert.SerializeObject(result, Formatting.Indented);

        Console.WriteLine(json);

    }

}