商场打折结构体

namespace 商场打折结构体
{
    class Program
    {
        struct ZhuangBei
        {
            public string name;
            public double price;
            public int amount;
       
        }
        static void Main(string[] args)
        {
            while (true)
            {
                Console.WriteLine("\t\t**********约里克超神店欢迎您的光临**********");
                double sum = 0;
                ArrayList al = new ArrayList();
                ZhuangBei a = new ZhuangBei();
                while (true)
                {   
                    Console.WriteLine("请输入您要购买的物品名称：");
                    a.name = Console.ReadLine();
                    Console.WriteLine("请输入单价：");
                    a.price = Convert.ToInt32(Console.ReadLine());
                    Console.WriteLine("请输入数量：");
                    a.amount = Convert.ToInt32(Console.ReadLine());
                    al.Add(a);
                    Console.WriteLine("您是否需要结账(Y/N)");
                    string x = Console.ReadLine(); 
                    if (x == "Y")
                    {
                        break;
                    }
                } //第二个while的花括号

for (int i = 0; i < al.Count; i++)
                        {
                            sum =sum+ ((ZhuangBei)al[i]).price * ((ZhuangBei)al[i]).amount;
                        }
                      
                    if (sum < 3000)
                    {
                        sum = sum * 1;
                    }
                    if(sum>3000&&sum<=4000)
                    {
                        sum = sum * 0.9;
                    }
                    if (sum > 4000 )
                    {
                        sum = sum * 0.8;
                    }
                    Console.WriteLine("折后价："+sum);
                Console.WriteLine("欢迎再次光临");
            } //第一个while的花括号
        }
    }
}