using System;

using System.Linq;

using System.Collections.Generic;

​

static class Program

{

    public static void Main(string[] args)

    {

        // Task1

        var collection1 = new int[] { 1, 2, 3, 5 };

        Print(SquareHelper.GetOddSqrtItems(collection1));

​

        Console.WriteLine("\n--------------\n");

​

        // Task2

        var monthCollection1 = new MonthsCollection();

        var monthCollection2 = new MonthsCollection();

​

        Print(monthCollection1.GetMonth(10));

        Print(monthCollection2.GetMonth(30));

    }

​

    public static void Print<T>(IEnumerable<T> source)

    {

        foreach (var item in source)

        {

            Console.WriteLine(item?.ToString());

        }

    }

}

public static class SquareHelper

    {

        public static IEnumerable<decimal> GetOddSqrtItems<T>(IEnumerable<T> source) where T : struct

        {

            var sourceArray = source.ToArray();

            for (int i = 0; i < sourceArray.Length; i++)

            {

                var decimalValue = Convert.ToDecimal(sourceArray[i]);

                if (decimalValue % 2 != 0)

                {

                    yield return decimalValue * decimalValue;

                }

                else 

                {

                    //yield return decimalValue;

                }

            }

        }

    }

​

public class Month

    {

        public Month(int id, string name, int days) 

        {

            Id = id;

            Name = name;

            Days = days;

        }

​

        public int Id { get; set; }

        public string Name { get; set; }

        public int Days { get; set; }

​

        public override string ToString()

        {

            return $"{Id}:{Name}:{Days}";

        }

    }

​

public class MonthsCollection

    {

        private readonly Month[] _month;

​

        public MonthsCollection()

        {

            _month = new Month[]

            {

                new Month(1, "January", 31),

                new Month(2, "February", 28),

                new Month(3, "March", 31),

                new Month(4, "April", 30),

                new Month(5, "May", 31),

                new Month(6, "June", 30),

                new Month(7, "July", 31),

                new Month(8, "August", 31),

                new Month(9, "September", 30),

                new Month(10, "October", 31),

                new Month(11, "November", 30),

                new Month(12, "December", 31)

            };

        }

​

        public Month[] GetMonth(int indexOrCount)

        {

            if (indexOrCount < 12)

            {

                indexOrCount = indexOrCount == 0 ? 0 : indexOrCount - 1;

                return new Month[] { _month[indexOrCount] };

            }

            else

            {

                return _month.Where(x => x.Days == indexOrCount).ToArray();

            }

        }

    }