Task 7

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

namespace ООП
{
    class Program
    {
        static void Main(string[] args)
        {
            Proop stock = new Proop(new List<Squad>{
            new Squad("Abc"),
            new Squad("Bcd"),
            new Squad("Cde"),
            new Squad("Def"),
            new Squad("Efg"),
            },
            new List<Squad>{
            new Squad("Tom"),
            new Squad("Bom"),
            new Squad("Som"),
            new Squad("Gom"),
            new Squad("Won"),
            }
            );

            stock.Work();
        }
    }

    class Squad
    {
        public string Name { get; private set; }

        public Squad(string name)
        {
            Name = name;
        }

        public void ShowInfo()
        {
            Console.WriteLine(Name);
        }
    }

    class Proop
    {
        private List<Squad> _first = new List<Squad>();

        private List<Squad> _second = new List<Squad>();

        public Proop(List<Squad> first, List<Squad> second)
        {
            _first = first;
            _second = second;
        }

        public void Work()
        {
            ShowAll();
            TransferOfSoldiers();
            ShowAll();

            Console.ReadKey();
        }

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

        private void TransferOfSoldiers()
        {
            string letter = "B";

            var result = _first.Where(solder => solder.Name.StartsWith(letter));
            _second = _second.Union(result).ToList();
            _first = _first.Except(result).ToList();
        }

        private void ShowAll()
        {
            Console.WriteLine($"   ===Отряды===\n-Первый отряд-");
            ShowInfo(_first);
            Console.WriteLine($"-Второй отряд-");
            ShowInfo(_second);
            Console.WriteLine($"   ===Конец списка===\n");
        }
    }
}