生成不重复的随机数数组，算法优化

        private void Form1_Load(object sender, EventArgs e)
        {
            string result = "";
            System.Diagnostics.Stopwatch watch = new System.Diagnostics.Stopwatch();

            watch.Start();
            List<int> list = new List<int>();
            Random random = new Random();
            while (list.Count < 100)
            {
                int t = random.Next(0, 100);
                if (!list.Contains(t))
                {
                    list.Add(t);
                }
            }
            watch.Stop();

            result += "A:" + watch.ElapsedTicks.ToString();

            watch.Restart();

            int[] arr = new int[100];
            int[] buf = new int[100];

            for (int i = 0; i < 100; i++)
            {
                buf[i] = i;
            }

            Random ran = new Random();
            int bufLength = buf.Length;
            for (int i = 0; i < 100; i++)
            {
                int t = ran.Next(0, bufLength);
                arr[i] = buf[t];
                buf[t] = buf[bufLength - 1];
                bufLength--;
            }
            watch.Stop();

            result += "  B:" + watch.ElapsedTicks.ToString();

            MessageBox.Show(result);
            this.Close();
        }