$h = $f*$h + 1; // 1, 4, 13, 40, 121, 364, 1093, ... while ($h >= 1){ // 将数组变为h有序 for ($i = $h; $i < $len; $i++){ // 将a[i]插入到a[i-h], a[i-2*h], a ...

[Shellsort](http://en.wikipedia.org/wiki/Shellsort), also known as the **diminishing increment sort**, is one of the oldest sorting algorithms, named after its ...