using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Lab3
{
    class Program
    {
        public static void Main(string[] args)
        {
            List<int> compressed = Compress(Console.ReadLine());
            Console.WriteLine(string.Join(", ", compressed));
            string decompressed = Decompress(compressed);
            Console.WriteLine(decompressed);
            var file1 = File.Open("test1.txt", FileMode.Open);
            var file2 = File.Open("test2.txt", FileMode.Open);
            Console.WriteLine($"Size of compressed file: {file1.Length} byte");
            Console.WriteLine($"Size of decompressed file: {file2.Length} byte");
            file1.Dispose();
            file2.Dispose();
            Console.ReadKey();
        }

        public static List<int> Compress(string uncompressed)
        {
            Dictionary<string, int> dictionary = new Dictionary<string, int>();
            for (int i = 0; i < 256; i++)
                dictionary.Add(((char)i).ToString(), i);

            string w = string.Empty;
            List<int> compressed = new List<int>();

            foreach (char c in uncompressed)
            {
                string wc = w + c;
                if (dictionary.ContainsKey(wc))
                {
                    w = wc;
                }
                else
                {
                    compressed.Add(dictionary[w]);
                    dictionary.Add(wc, dictionary.Count);
                    w = c.ToString();
                }
            }

            if (!string.IsNullOrEmpty(w))
                compressed.Add(dictionary[w]);
            var array = new StringBuilder();
            foreach(var el in compressed)
            {
                array.Append($"{el.ToString()} ");
            }
            File.WriteAllText("test1.txt", array.ToString());
            return compressed;
        }

        public static string Decompress(List<int> compressed)
        {
            Dictionary<int, string> dictionary = new Dictionary<int, string>();
            for (int i = 0; i < 256; i++)
                dictionary.Add(i, ((char)i).ToString());

            string w = dictionary[compressed[0]];
            compressed.RemoveAt(0);
            StringBuilder decompressed = new StringBuilder(w);

            foreach (int k in compressed)
            {
                string entry = null;
                if (dictionary.ContainsKey(k))
                    entry = dictionary[k];
                else if (k == dictionary.Count)
                    entry = w + w[0];

                decompressed.Append(entry);

                dictionary.Add(dictionary.Count, w + entry[0]);

                w = entry;
            }
            File.WriteAllText("test2.txt", decompressed.ToString());
            return decompressed.ToString();
        }
    }
}