输出前n个整数的阶乘(1+2!+3!+...+n!)的和,要求n的值由键盘输入,用C#编程

Question

如题所述

Answer 1

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace Factorial
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.Write("请输入一个整数：");
            long n = long.Parse(Console.ReadLine());
            long i=1;
            long result=1;
           while(i<=n)
           {
               result *= i;
               i++;
           }
           Console.WriteLine("{0}!={1}",n,result);
           Console.ReadLine();
        }
    }
}