算法练习五：求数组中第k大的数

 static int FindK(IList<int> a, int k)
        {
            IList<int> listTemp;
            int start=0;
            int end = a.Count-1;
            int middle = (start + end) / 2;
            //int a=
            //listTemp.a
            int position = -1;
          
            int count = 1;
            while (position != k)
            {
                if (position < k&& position!=-1)
                {
                    k = k - position-1;
                    //if (count % 2 == 0)
                    //{
                    //    k--;
                    //}
                    //count++;
                   
                   
                }
                listTemp = new List<int>();
                listTemp.Add(a[middle]);
                position = 0;
                for (int i = start; i <= end; i++)
                {
                    if (i != middle)
                    {
                        if (a[i] <= a[middle])
                        {
                            listTemp.Insert(position,a[i]);
                            position++;
                        }
                        else
                        {
                            listTemp.Add(a[i]);
                        }
                    }
                }
              

                a = listTemp;
                if (listTemp.Count == 1)
                    return a[position];
                if (position < k)
                {
                    //if (position + 1 == k)
                    //{
                    //    return a[position];
                    //}
                    start = position +1;
                    //a = listTemp;
                    end = listTemp.Count-1;
                    middle = (start + end) / 2;
                }
                if (position >k)
                {
                    start = 0;
                    end = position-1 ;
                   
                    middle = (start + end) / 2;

                }
            }

            return a[position];
        }