using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;namespace CS00023
{
    class Program
    {
        static int countSum(int lenght)
        {
            int temp = 0, sum = 0,counter;
            for (counter = 1; counter <= lenght; counter++)
            {
                temp = temp * 10 + 2;
                sum = sum + temp;
            }
            return sum;
        }
         static void Main(string[] args)
        {
            int len;
            Console.WriteLine("等式求和2+22+222+222+...+222~~22(n为2的个数)");
            Console.Write("请输入n的值:\n n=");
            len= Console.Read();
            Console.WriteLine("等式求和结果:Sum={0}", countSum(len));
            Console.ReadKey();
        } 
    }
}功能:实现2+22+222+22...2  的功能
刚学习不知道为什么得到的结果是随机数?