冒泡排序

static void Main(string[] args)
        {
            int[] scores = new int[5];
            int i,j;
            int temp;
            Console.WriteLine("请输入5个学员的成绩：");
            for (i = 0; i < 5; i++)
            {
                Console.WriteLine("请输入第{0}个学员的成绩",i + 1);
                scores[i] = int.Parse(Console.ReadLine());
            }

            for (i = 0; i < scores.Length -1; i++)
            {
                for (j = 0; j < scores.Length -1 - i; j++)
                {
                    if (scores[j] > scores[j+1])
                    {
                        temp = scores[j];
                        scores[j] = scores[j+1];
                        scores[j + 1] = temp;
                    }
                }
            }
            Console.WriteLine("排序后：");
            for (i = 0; i < scores.Length; i++)
            {
                Console.WriteLine("{0}\t",scores[i]);
            }
            Console.ReadLine();
        }

口诀（升序）：

N个数字来排序，两两相比小靠前

外层循环 I-1，内存循环 I-1-J

如果要降序，只把大于换小于