using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

public class Program

{

    public static void Main()

    {

        string searchTerm = "The Lord Of The Rings";

        searchTerm = NormalizeWhiteSpacesAndPunctuations(searchTerm); // no op in this case but you should do it if searchTerm is an input

        List<string> films = new List<string>() { "Harry Potter", "Avangers", "The Lord  Of The Rings", "Back to the future" };

        string film = films

            .FirstOrDefault(film => NormalizeWhiteSpacesAndPunctuations(film).IndexOf(searchTerm, StringComparison.OrdinalIgnoreCase) >= 0);

        Console.WriteLine(film);

    }

     static string NormalizeWhiteSpacesAndPunctuations(string text)

    {

        if (string.IsNullOrWhiteSpace(text))

            return string.Empty;

​

        text = text.Trim();

        StringBuilder sb = new StringBuilder(text.Length);

        bool lastCharWasSpace = false;

        foreach (char c in text)

        {

            if (char.IsWhiteSpace(c) || char.IsPunctuation(c))

            {

                // prevent consecutive spaces, only one should remain

                if (!lastCharWasSpace)

                {

                    sb.Append(' ');

                    lastCharWasSpace = true;

                }

            }

            else

            {

                sb.Append(c);

                lastCharWasSpace = false;

            }

        }

​

        return sb.ToString().Trim();

    }

}