qsort C#

        const int MAX = 1000000;
        static Random rand = new Random();
        static int[] a = new int[MAX];

        static void test()
        {
            Stopwatch sw = new Stopwatch();
            sw.Start();

            for (int t = 0; t < 10; t++)
            {
                for (int i = 0; i < MAX / 2; i++)
                    a[i] = a[MAX - i - 1] = i;
                Array.Sort(a);
            }

            Console.WriteLine(sw.ElapsedMilliseconds);
            sw.Restart();

            for (int t = 0; t < 10; t++)
            {
                for (int i = 0; i < MAX / 2; i++)
                    a[i] = a[MAX - i - 1] = i;

                for (int i = 0; i < MAX/2; i++)
                {
                    int x = rand.Next(MAX);
                    int y = rand.Next(MAX);
                    int tmp = a[x]; a[x] = a[y]; a[x] = tmp;
                }

                Array.Sort(a);
            }

            Console.WriteLine(sw.ElapsedMilliseconds);

        }