将序列(p, h, n, d, y, a, f, q, x, m, c, e)中的关键码按字母升序重新排序,初始步长为4的shell排序一趟扫描的结果为(用一个空格分隔字母)Sort the key of sequence (p, h, n, d, y, a, f, q, x, m, c, e) in ascending alphabetical order. The result of a round of shell sorting with the initial step size 4 is ? (Separate the letter by a space)