Belov_HW_CS1

using System;

namespace Example
{
    class MyApplication
    {
        private static void First()
        {
            Console.WriteLine("ПЕРВОЕ ЗАДАНИЕ");
            int result = 0;
            for (int i = 0; i < 10; i++)
            {
                result += 2;
                Console.WriteLine(result.ToString());
            }
            Console.ReadKey();
            Console.Clear();
        }
        private static void Second(int min, int max)
        {
            Console.WriteLine("ВТОРОЕ ЗАДАНИЕ");
            int sum = 0;
            for (int i = min; i <= max; i++)
                sum += i;
            Console.WriteLine("Результат: {0}", sum);
            Console.ReadKey();
            Console.Clear();
        }
        private static void Third(int min, int max)
        {
            Console.WriteLine("ТРЕТЬЕ ЗАДАНИЕ");
            int sum = 0;
            int mult = 1;
            for (int i = min; i <= max; i++)
            {
                if (i % 2 == 0)
                    sum += i;
                else
                    mult *= i;
            }
            Console.WriteLine("Результат: {0}, {1}", sum, mult);
            Console.ReadKey();
            Console.Clear();
        }
        private static void Fourth()
        {
            Console.WriteLine("ЧЕТВЕРТОЕ ЗАДАНИЕ");
            int sum = 0;
            for (int i = 0; i <= 100; i++)
                if (i % 3 == 0)
                    Console.WriteLine(i.ToString());
            Console.ReadKey();
            Console.Clear();
        }
        private static void Fifth(int number)
        {
            Console.WriteLine("ПЯТОЕ ЗАДАНИЕ");
            int result = 1;
            for (int i = 1; i <= number; i++)
                result *= i;
            Console.WriteLine("Результат: {0}", result);
            Console.ReadKey();
            Console.Clear();
        }
        private static void Sixth(int number, int power)
        {
            int result = number;
            Console.WriteLine("ШЕСТОЕ ЗАДАНИЕ");
            for (int i = 0; i < power; i++)
                result *= number;
            Console.WriteLine("Результат: {0}", result);
            Console.ReadKey();
            Console.Clear();
        }
        private static void Seventh(int number)
        {
            Console.WriteLine("СЕДЬМОЕ ЗАДАНИЕ");
            int numbers_count = 0;
            int sum = 0;
            if (number == 0)
                numbers_count++;
            while (number != 0)
            {
                sum += number - number / 10 * 10;
                number /= 10;
                numbers_count++;
            }
            Console.WriteLine("Результат: {0}, {1}", sum, numbers_count);
            Console.ReadKey();
            Console.Clear();
        }
        private static void Eighth(int number)
        {
            Console.WriteLine("ВОСЬМОЕ ЗАДАНИЕ");
            int result = 0;
            result += number - number / 10 * 10;
            number /= 10;
            while (number != 0)
            {
                result *= 10;
                result += number - number / 10 * 10;
                number /= 10;
            }
            Console.WriteLine("Результат: {0}", result);
            Console.ReadKey();
            Console.Clear();
        }
        private static void Ninth(int number)
        {
            Console.WriteLine("ДЕВЯТОЕ ЗАДАНИЕ");
            for (int i = 1; i <= number; i++)
            {
                if (number % i == 0)
                {
                    Console.WriteLine(i.ToString());
                }
            }
            Console.ReadKey();
            Console.Clear();
        }
        private static void Tenth(int number)
        {
            Console.WriteLine("ДЕСЯТОЕ ЗАДАНИЕ");
            for (int i = 2; i < number; i++)
            {
                if (number % i == 0)
                {
                    Console.WriteLine("Не простое.");
                    Console.ReadKey();
                    Console.Clear();
                    return;
                }
            }
            Console.WriteLine("Простое.");
            Console.ReadKey();
            Console.Clear();
        }
        private static void Eleventh(int number)
        {
            Console.WriteLine("ОДИННАДЦАТОЕ ЗАДАНИЕ");
            int prev = number - number / 10 * 10;
            number /= 10;
            while (number != 0)
            {
                if (prev == number - number / 10 * 10)
                {
                    Console.WriteLine("Есть.");
                    Console.ReadKey();
                    Console.Clear();
                    return;
                }
                prev = number - number / 10 * 10;
                number /= 10;
            }
            Console.WriteLine("Нет.");
            Console.ReadKey();
            Console.Clear();
        }
        private static void Twelfth(int number)
        {
            Console.WriteLine("ДВЕНАДЦАТОЕ ЗАДАНИЕ");
            int prev = number - number / 10 * 10;
            number /= 10;
            while (number != 0)
            {
                if (prev < number - number / 10 * 10)
                {
                    Console.WriteLine("Нет.");
                    Console.ReadKey();
                    Console.Clear();
                    return;
                }
                prev = number - number / 10 * 10;
                number /= 10;
            }
            Console.WriteLine("Да.");
            Console.ReadKey();
            Console.Clear();
        }
        public static void Main()
        {
            First();
            Second(1, 10);
            Third(1, 5);
            Fourth();
            Fifth(5);
            Sixth(5, 3);
            Seventh(1234);
            Eighth(1234);
            Ninth(50);
            Tenth(17);
            Tenth(20);
            Eleventh(11234);
            Eleventh(1234);
            Twelfth(11299);
            Twelfth(22044);
        }
    }
}