Abstract—Many algorithms are available for sorting the
unordered elements. Most important of them are Bubble sort, Heap
sort, Insertion sort and Shell sort. These algorithms have their own
pros and cons. Shell Sort which is an enhanced version of insertion
sort, reduces the number of swaps of the elements being sorted to
minimize the complexity and time as compared to insertion sort.
Shell sort improves the efficiency of insertion sort by quickly shifting
values to their destination. Average sort time is O(n1.25), while worst-
case time is O(n1.5). It performs certain iterations. In each iteration it
swaps some elements of the array in such a way that in last iteration
when the value of h is one, the number of swaps will be reduced.
Donald L. Shell invented a formula to calculate the value of ‘h’. this
work focuses to identify some improvement in the conventional Shell
sort algorithm. “Enhanced Shell Sort algorithm” is an improvement
in the algorithm to calculate the value of ‘h’. It has been observed
that by applying this algorithm, number of swaps can be reduced up
to 60 percent as compared to the existing algorithm. In some other
cases this enhancement was found faster than the existing algorithms
available.