//为了便于说明，数组里加了个重复的数字9
int[] a = { 9, -20, 9, 7, 37, 38, 69, 89, -1, 59, 29, 0, -25, 39, 900, 22, 13, 55 };

            int[] b = new int[10];
            List<int> positions = new List<int>();//我新加的，记录最小值的位置

            int intTmp = a[0], intMaxNum;

            for (int i = 0; i < a.Length; i++)
            {

                intTmp = a[i] >= intTmp ? a[i] : intTmp;//大于号改成大于等于

            }

            intMaxNum = intTmp;


            for (int j = 0; j < b.Length; j++)
            {
                int tpos = -1;//记录最小值的位置
                for (int i = 0; i < a.Length; i++)
                {

                    if (j == 0)
                    {
                        if (a[i] <= intTmp)
                        {//改写了，小于号改成小于等于
                            tpos = i;//关键是记录最小值的下标
                            intTmp = a[i];
                        }
                    }
                    else
                    {

                        if (positions.Contains(i) == false && a[i] >= b[j - 1])
                        {//改写了，检查最小值的下标是否已记录
                            if (a[i] <= intTmp)
                            {
                                tpos = i;
                                intTmp = a[i];
                            }
                        }
                    }
                }
                positions.Add(tpos);//把最小值的下标加入
                b[j] = intTmp;

                intTmp = intMaxNum;

            }

              foreach (int bb in b)

  {

  Console.WriteLine(bb);

 

  }

  Console.ReadLine();