using System;

using System.Collections.Generic;

using System.Text;

public class Program

{

    public static void Main()

    {

        /*"MyFavouriteChocIsDARKChocalate" should return "My Favourite Choc Is DARK Chocalate"*/

        var input = "MyFavouriteChocIsDARKChocalate";

        var split = SplitOnCaps(input);

        Console.WriteLine(input + " --> " + split);

        var match = "My Favourite Choc Is DARK Chocalate";

        Console.WriteLine(split == match ? "Match" : "No Match");       

    }

    public static string SplitOnCaps(string s)

    {

        var splits = new List<int>();

        var chars = s.ToCharArray();

        for(var i=1; i<chars.Length-1; i++)

        {

            if (IsCapital(chars[i]) && !IsCapital(chars[i+1]) ||

               IsCapital(chars[i]) && !IsCapital(chars[i-1]))

            {

                splits.Add(i);

            }

        }

​

        var sb = new StringBuilder();

​

        var lastSplit = 0;

        foreach(var split in splits)

        {

            sb.Append(s.Substring(lastSplit, split - lastSplit) + " ");

            lastSplit = split;

        }

        sb.Append(s.Substring(lastSplit));

        return sb.ToString();

    }

    public static bool IsCapital(char c)

    {

        var i = (int)c;

        return i>=65 && i<=90;

    }

}