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

namespace ConsoleApp1
{
    class Employee : IComparable<Employee>
    {
        public string LastName;
        public string Position;
        public int PhoneNumber;

        public Employee(string LastName, string Position, int PhoneNumber)
        {
            this.LastName = LastName;
            this.Position = Position;
            this.PhoneNumber = PhoneNumber;
        }

        public int CompareTo(Employee other)
        {
            return String.Compare(this.LastName, other.LastName);
        }
    }

    class Program
    {
        static int SearchPhoneByName(Employee[] array, int searchedValue, int first, int last)
        {
            if (first > last)
            {
                return -1;
            }
            var middle = (first + last) / 2;
            var middleValue = array[middle].PhoneNumber;

            if (middleValue == searchedValue)
            {
                return middle;
            }
            else
            {
                if (middleValue > searchedValue)
                {
                    return SearchPhoneByName(array, searchedValue, first, middle - 1);
                }
                else
                {
                    return SearchPhoneByName(array, searchedValue, middle + 1, last);
                }
            }
        }

        static void SortByAlphabet(ref Employee[] array)
        {
            for (int i = 0; i < array.Length-1; i++)
            {
                for (int j = i + 1; j < array.Length; j++)
                {
                    if (array[i].CompareTo(array[j]) > 0)
                    {
                        Employee temp = array[i];
                        array[i] = array[j];
                        array[j] = temp;
                    }
                }
            }

        }

        static void Main(string[] args)
        {
            string PathToSource = @"C:\Программа\Phone_Memory.txt";
            string PathToOutput = @"C:\Программа\Output.txt";

            int employyesCount = 0;

            using (StreamReader strReader = new StreamReader(PathToSource))
            {
                string line;
                while ((line = strReader.ReadLine()) != null)
                {
                    employyesCount++;
                }
            }

            employyesCount /= 3;
            Employee[] phoneMemory = new Employee[employyesCount];

            Console.WriteLine($"{employyesCount} работников записано в телефоне");

            using (StreamReader strReader = new StreamReader(PathToSource))
            {
                for (int i = 0; i < employyesCount; i++)
                {
                    string name = strReader.ReadLine();
                    string position = strReader.ReadLine();
                    int phoneNumber = int.Parse(strReader.ReadLine());
                    phoneMemory[i] = new Employee(name, position, phoneNumber);
                }
            }
            SortByAlphabet(ref phoneMemory);

            string NameForSearch = Console.ReadLine();
            int SearchPhone = 0;
            for (int i = 0; i < employyesCount; i++)
            {
                if (phoneMemory[i].LastName == NameForSearch)
                    SearchPhone = phoneMemory[i].PhoneNumber;
            }

            var SearchResult = SearchPhoneByName(phoneMemory, SearchPhone, 0, phoneMemory.Length - 1);
            using (StreamWriter strWriter = new StreamWriter(PathToOutput, true))
            {
                if (SearchResult < 0)
                    strWriter.WriteLine("Номер не найден");
                else
                    strWriter.WriteLine("Номер найден. Индекс элемента со значением {0} равен {1}", SearchPhone, SearchResult);
            }
            Console.Read();
        }
    }
}