for循环

            #region 统计1-1000之和

            int sum = 0;
             for (int i = 1; i<=100; i++)//i++ =>  I=i+1,结束后i值为101.i--
            { 
                sum += i; //sum=sum+i
            }
            Console.WriteLine($"最后结果为{sum}");
            #endregion

            for (int i = 1; i <= 100; i=i+2)//i++ =>  I=i+1 i+=2
            {
                sum += i; //sum=sum+i

   int a, b, c;
            for (int d = 100; d <= 999; d++)
            {
                a = d / 100;
                b = d / 10 % 10;
                c = d % 10;
                if (d==a*a*a+b*b*b+c*c*c)
                {
                    Console.WriteLine($"则水仙花数为{d}");

                }
            }

 

            }
            Console.WriteLine($"最后结果为{sum}");
      
        }