task44

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

public class Program
{
    public static void Main(string[] args)
    {
        Army army = new Army();
        army.ShowSoldiersGroups();
        army.DraftSoldiers();
        army.ShowSoldiersGroups();
    }
}

public class Army
{
    private Random _random;
    private List<Soldier> _soldiersGroupFirst;
    private List<Soldier> _soldiersGroupSecond;

    public Army()
    {
        _soldiersGroupFirst = new List<Soldier>();
        _soldiersGroupSecond = new List<Soldier>();
        _random = new Random();
        CreateSoldiers(_soldiersGroupFirst);
        CreateSoldiers(_soldiersGroupSecond);
    }

    public void ShowSoldiersGroups()
    {
        Console.WriteLine("\nFirst Group : ");
        PrintSoldiers(_soldiersGroupFirst);

        Console.WriteLine("\nSeond Group : ");
        PrintSoldiers(_soldiersGroupSecond);
    }

    public void DraftSoldiers()
    {
        string letterSurnameStart = "B";

        Console.WriteLine("\n\nDraft Soldiers from Group First to Group Second.\n");

        var soldiersFiltered = _soldiersGroupFirst.Where(soldier => soldier.Surname.StartsWith(letterSurnameStart));
        _soldiersGroupSecond.AddRange(soldiersFiltered);
        _soldiersGroupFirst = _soldiersGroupFirst.Where(soldier =>
                                                        soldier.Surname.StartsWith(letterSurnameStart) != true).
                                                  ToList();
    }

    private void PrintSoldiers(List<Soldier> soldiers)
    {
        Console.WriteLine();

        foreach (var soldier in soldiers)
            Console.WriteLine(soldier);
    }

    private void CreateSoldiers(List<Soldier> soldiers)
    {
        string[] names = { "Nick", "Rick", "Dick", "Virgil", "Dante" };
        string[] surnames = {
            "Alonso",
            "Álvarez",
            "Andrade",
            "Ávalos",
            "Ávila",
            "Barrios",
            "Beltrán",
            "Benítez",
            "Blanco",
            "Bonilla",
            "Bravo",
            "Cárdenas",
            "Córdova",
            "Dávila",
            "Díaz",
            "Gómez",
        };

        string[] ranks = {
            "silver",
            "silver elite",
            "silver elite master",
            "gold nova",
            "master guardian",
            "distinguished master guardian",
            "legendary eagle",
            "supreme master first class",
            "global elite"
        };

        int soldiersAmountMinimum = 10;
        int soldiersAmountMaximum = 100;

        int amountSoldiers = _random.Next(soldiersAmountMinimum, soldiersAmountMaximum);

        string name;
        string surname;
        string rank;

        for (int i = 0; i < amountSoldiers; ++i)
        {
            name = names[_random.Next(names.Length)];
            surname = surnames[_random.Next(surnames.Length)];
            rank = ranks[_random.Next(ranks.Length)];
            soldiers.Add(new Soldier(name, surname, rank));
        }
    }
}

public class Soldier
{
    public string Name { get; private set; }
    public string Surname { get; private set; }
    public string Rank { get; private set; }

    public Soldier(string name, string surname, string rank)
    {
        Name = name;
        Surname = surname;
        Rank = rank;
    }

    public override string ToString()
    {
        return String.Format($"{Name} {Surname} - {Rank}");
    }
}