有一组数据3,5,9,7,4,13,15,0,2,20.已知最大数是20，把数据从小到大排序，而且算法复杂度只能是1

public void Sort()
{
    int[] a ={ 3, 5, 9, 7, 4, 13, 15, 0, 2, 20 };
    bool[] b = new bool[21];
    for (int i = 0; i < a.Length; i++)
    {
        b[a[i]] = true;
    }
    for (int i = 0; i < b.Length; i++)
    {
        if (b[i])
            Console.WriteLine(i + ",");
    }
    Console.ReadLine();
}