递归

1、简单的递归算法

        static void Main(string[] args)
        {
            Console.WriteLine(Fun1(5));
            Console.WriteLine(Fun2(5));
        }

        /// <summary>
        /// 2的幂次方
        /// </summary>
        /// <param name="i">幂</param>
        /// <returns>返回值</returns>
        private static int Fun1(int i)
        {
            if (i == 1)
            {
                return 2;
            }
            return Fun1(i - 1) * 2;
        }

        /// <summary>
        /// 阶乘
        /// </summary>
        /// <param name="i">最高数</param>
        /// <returns>返回值</returns>
        private static int Fun2(int i)
        {
            if (i == 1)
            {
                return 1;
            }
            return Fun2(i - 1) * i;
        }

结果：