using System;

​

public class Program

{

    public static void Main(string[] args)

    {

        string inputText = "Текстът за обработка.";

        string[] words = ExtractWords(inputText);

        DataProcessor dataProcessor = new DataProcessor(words);

        char firstLetter = 'м';

        char lastLetter = 'н';

        string[] matchingWords = dataProcessor.FindWordsByPattern(firstLetter, lastLetter);

        Console.WriteLine("Брой думи с шаблон: {matchingWords.Count}");

        Console.WriteLine("Брой уникални думи с шаблон: {matchingWords.Distinct().Count()}");

        foreach (var word in matchingWords)

        {

            Console.WriteLine(word);

        }

    }

​

    static string[] ExtractWords(string text)

    {

        return text.Split(new[] { ' ', ',', '.', '!', '?' }, StringSplitOptions.RemoveEmptyEntries);

    }

}

​

class DataProcessor

{

    private string[] words;

    public DataProcessor(string[] words)

    {

        this.words = words;

    }

​

    public string[] FindWordsByPattern(char firstLetter, char lastLeeter)

    {

        return this.words;//this.words.Where(word => word.ToLower()[0] == char.ToLower(firstLetter) && word.ToLower()[word.Length - 1] == char.ToLower(lastLetter)).ToArray();

    }

}