using System;
namespace Lesson
{
    class Program
    {
        #region 练习题一 课上有不写了
        #endregion



        #region 练习题二
        static int JieCheng(int max)
        {
            if (max == 0)
            {
                return 1;
            }
            else 
            { 
                return max * JieCheng(max - 1); 
            }
                
        }

        #endregion



        #region 练习题三
        static int JieChengHe(int num)
        {
            if (num == 1)
            {
                return JieCheng(1);
            }
            return JieCheng(num) + JieChengHe(num-1);
        }
        #endregion



        #region 练习题四
        static void Bamboo(float length, int day)
        {
            Console.WriteLine("长度为" + length);
            length /= 2;
            day--;
            if (day < 0)
            {
                Console.WriteLine("长度为" + length);
                return;
            }
            Bamboo(length, day);
        }
        #endregion


        #region 练习题五
        static bool Fun(int num)
        {
            Console.WriteLine(num);
            return num == 200 || Fun(num + 1);
        }
        #endregion




        static void Main(string[] args)
        {
            Console.WriteLine(JieCheng(5));

            Console.WriteLine(JieChengHe(10));

            Bamboo(100,10);

            Fun(0);
        }
    }
}