using System;

using System.Collections;                   

public class Program

{

    public static void Main()

    {

          string entireText = @"Here is google.

Here is MS.";

             ArrayList paragraphs = paragraphs_method(entireText);

            ArrayList containingWordList = new ArrayList();

            foreach (String paragraph in paragraphs){

                if (!containingWordList.Contains(paragraph)){ containingWordList.Add(paragraph);}

            }

        Console.WriteLine("section:"+ string.Join(",",containingWordList.ToArray()));

    }

     public static ArrayList paragraphs_method(string entireText)

    {

        char[] sep1 = new char[] { '\r', '\n', '\r', '\n' };

        char[] sep2 = new char[] { '\n', '\n' };

​

        string[] chunks = entireText.Split(sep1);

        ArrayList paragraphs = new ArrayList();

        foreach (string chunk in chunks)

        {

​

            string[] paras = chunk.Split(sep2);

            foreach (string paragraph in paras)

                paragraphs.Add(paragraph.Trim());

        }

        return paragraphs;

    }

​

}