从50个数里面取9个不重复的随机数

class Program
    {
        static void Main(string[] args)
        {
            Random r = new Random();
            int[] num = new int[9];
            for (int i = 0; i < num.Length; i++)
            {
                num[i] = r.Next(0, 51);
                for (int j = 0; j < i; j++)
                {
                    if (num[j] == num[i])
                    {
                        i--;
                        break;

                    }
                }
            }
            for (int l = 0; l < num.Length; l++)
            {
                Console.WriteLine(num[l]);
            }
            Console.ReadLine();
        }
    }