B. Shell Sort
The first diminishing increment sort. On each pass, ‘i’ sets
of n/i items are sorted, typically with insertion sort. On each
succeeding pass, i is reduced until it is 1 for the last pass. A
good series of i values is important to efficiency [1].
Invented by Donald Shell in 1959, the shell sort is the most
efficient of the O(n2
) class of sorting algorithms [4]. Of
course, the shell sort is also the most complex of the O(n2
)
algorithms.