集合，ArrayList

用集合代替数组：

            Console.Write("请输入人数：");
            int renshu = int.Parse(Console.ReadLine());
         ArrayList chengji = new ArrayList();
            if (renshu >= )
            {
                for (int h = ; h <= renshu; h++)
                {
                    Console.Write("请输入第" + h + "个人成绩");
                    chengji.Add(int.Parse(Console.ReadLine()));
                }
                chengji.Sort();
                foreach (int a in chengji)
                {
                    Console.Write(a+" ");
                }

                int he = ;
                for (int i = ; i <= renshu - ; i++)
                {
                    he = he + (int)chengji[i];
                }
                double pj = (he - (int)chengji[] - (int)chengji[] - (int)chengji[renshu - ] -(int)chengji[renshu - ] / (renshu - ));
                Console.Write("去掉两个最低分"+chengji[]+"，"+chengji[]+"去掉两个最高分"+chengji[renshu - ]+"，"+chengji[renshu - ]+"最后的成绩是："+pj);

            }
            else
            {
                Console.WriteLine("您输入的人数要大于等于5！！！");
            }
            Console.ReadLine();

foreach查询多为数组：

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