Huyandex

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

namespace IndexSearch
{
    class Program
    {
        static void Main(string[] args)
        {
            Search s = new IndexSearch.Search(System.IO.Path.GetDirectoryName(System.Reflection.Assembly.GetExecutingAssembly().Location) + @"\Query");
            DateTime now = DateTime.Now;
            Dictionary<string, Dictionary<long, string>> Index = new Dictionary<string, Dictionary<long, string>>(s.BuildIndex());
            Console.WriteLine("Time elapsed after indexing: " + DateTime.Now.Subtract(now).Milliseconds + "ms");

            foreach (var v in Index)
            {
                Console.WriteLine(v.Key);
                foreach (var k in v.Value)
                {
                    Console.WriteLine(k.Key + " " + k.Value);
                }
            }


            s.Find(Console.ReadLine(), Index);
            Console.ReadLine();
        }
    }
}




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

namespace IndexSearch
{
    class Search
    {
        // A string that contains a path to folder with files
        private string Path;


        public Search (string Path)
        {
            this.Path = Path;
        }

        public Dictionary<string, Dictionary<long, string>> BuildIndex()
        {
            Dictionary<string, Dictionary<long, string>> Index = new Dictionary<string, Dictionary<long, string>>();
            string[] Files;
            Files = System.IO.Directory.GetFiles(Path);
            foreach (string s in Files)
            {
                using (FileStream fs = new FileStream(s, FileMode.Open, FileAccess.Read))
                {
                    int curByte;
                    string curWord = null;
                    while (true)
                    {
                        curByte = fs.ReadByte();
                        if (curByte < 0)
                        {
                            if (curWord != null)
                            {
                                if (!Index.ContainsKey(curWord))
                                {
                                    Index.Add(curWord, new Dictionary<long, string>());
                                    Index[curWord].Add(fs.Position - curWord.Length, s);
                                    curWord = null;
                                    break;
                                }
                                else
                                {
                                    Index[curWord].Add(fs.Position - curWord.Length, s);
                                    curWord = null;
                                    break;
                                }
                            }
                            else
                            {
                                break;
                            }
                        }

                        if (char.IsLetterOrDigit((char)curByte))
                        {
                            curWord += (char)curByte;
                        }
                        else
                        {
                            if (curWord == null) { continue; }
                            if (!Index.ContainsKey(curWord))
                            {
                                Index[curWord] = new Dictionary<long, string>();
                                Index[curWord].Add(fs.Position - curWord.Length, s);
                                curWord = null;
                            }
                            else
                            {
                                Index[curWord][fs.Position - curWord.Length] = s;
                                curWord = null;
                            }
                        }
                    }
                }
            }

            return Index;
        }

        public void Find(string Query, Dictionary<string, Dictionary<long, string>> Index)
        {
            if (Index.ContainsKey(Query))
            {
                Console.WriteLine("Нашлось запрошенное слово \"" + Query + "\" в: ");
                foreach (var v in Index[Query])
                {
                    Console.WriteLine(v.Value + " " + v.Key);
                }
            }
            else
            {
                Console.WriteLine("Слово не найдено.");
            }
        }
    }
}