gistfile1.txt

using System;
using System.Collections.Generic;
using System.Linq;

namespace project4
{
    internal class Program
    {
        static void Main(string[] args)
        {
            SolderDatabase solderDatabase = new SolderDatabase();
            solderDatabase.Work();
        }
    }

    class UserUtils
    {
        private static Random s_random = new Random();

        public static int GenerateRandomNumber(int min, int max)
        {
            return s_random.Next(min, max);
        }
    }

    class SolderDatabase
    {
        private List<Solder> _solders1 = new List<Solder>();

        private List<Solder> _solders2 = new List<Solder>();

        public SolderDatabase()
        {
            Fill(_solders1);

            Fill(_solders2);
        }

        public void Work()
        {
            Console.WriteLine("Добро пожаловать в базу солдат.");

            ShowAllInfo(_solders1);
            Console.WriteLine();

            ShowAllInfo(_solders2);
            Console.WriteLine();

            var filteredSolders = _solders1.Where(solder => solder.Name.ToUpper().StartsWith("Б"));
            
            _solders2 = _solders2.Union(filteredSolders).ToList();

            ShowAllInfo(_solders2);
        }        

        private void ShowAllInfo(List<Solder> solders)
        {
            foreach (var solder in solders)
            {
                solder.ShowInfo();
            }

            Console.WriteLine();
        }

        private void Fill(List<Solder> solders)
        {
            int maxNumberOfSolders = 10;
            int minPeriodOfService = 1;
            int maxPeriodOfService = 25;

            string[] names = new string[] { "Иванов", "Сидоров", "Бобров", "Петров", "Бабаев", "Прохоров", "Сергеев", "Бубнов", "Соловьев" };
            string[] weapons = new string[] { "Автомат", "Пулемет", "Гранатомет", "Танк", "САУ", "Пистолет" };
            string[] ranks = new string[] { "Рядовой", "Лейтенант", "Капитан", "Майор", "Полковник", "Подполковник" };

            for (int i = 0; i < maxNumberOfSolders; i++)
            {
                solders.Add(new Solder(names[UserUtils.GenerateRandomNumber(0, names.Length)], weapons[UserUtils.GenerateRandomNumber(0, weapons.Length)],
                    ranks[UserUtils.GenerateRandomNumber(0, ranks.Length)], UserUtils.GenerateRandomNumber(minPeriodOfService, maxPeriodOfService)));
            }
        }
    }

    class Solder
    {
        public Solder(string name, string weapon, string rank, int militaryServicePeriod)
        {
            Name = name;
            Weapon = weapon;
            Rank = rank;
            MilitaryServicePeriod = militaryServicePeriod;
        }

        public string Name { get; private set; }

        public string Weapon { get; private set; }

        public string Rank { get; private set; }

        public int MilitaryServicePeriod { get; private set; }

        public void ShowInfo()
        {
            Console.WriteLine($"Имя: {Name}, Оружие: {Weapon}, Звание: {Rank}, Срок службы: {MilitaryServicePeriod}");
        }
    }
}