Essay --

DATA STRUCTURES AND ALGORITHMTopic SHELL SORTNames Maryum Waris Tahir khan Isra Jameil Farrukh Ahsan Semester III Section ASubmitted to Sajid SaleemINTRODUCTIONShell sort, also known as diminishing increment sort, was devised by Donald Shell in 1959.It is known to be i of the long-standing sorting algorithm.The basic logic of this sort is that it virtually divides the original list into smaller list, which consists of elements which are present at a specified orifice, and performs sorting. As the gap decreases original list becomes more and more choose ,finally when gap is reduced to one, comparison between adjacent elements of list occurs which finally sorts the list.Shell sort utilizes interpellation sort.SHELL SORTWhile sorting a list, insertion sort compares first two elements of list (we consider a list with array found implementation) and sorts them, such that first and second element of list are arranged in required order. After this initial step, third element is involved and is sorted according to the two elements previously sorted and so on.Short comings of insertion sortWhile performing insertion sort if list is arranged in most unsorted manner(worst case) or list of to be sorted is lengthy, the process can be extremely time consuming as it involves the comparison and constitution of every new element considered with other elements already sorted.Improvements with shell sortIf the list is comparatively sorted with slight disordering, it is easier to sort the list as it give require less swapping upon comparison of elements in the listShell sort improves the sorting process because it compares and non adjoining elements which are far apart, and swaps th... ... and 10 while shoes 13- organise J = SPACE + 1 initialize counter J4-Repeat step 5 ,6 and 9 while J N5-Set K = J - SPACE initialize counter K6-Repea t step 7 and 8 while K 17-If ARRAYK+SPACEa-Interchange ARRAYK+SPACE and ARRAYKend of if structure8-Set K = K-SPACE decrements counter K end of while loop in step 69-Set J = J+1 increments counter J end of while loop in step 4 10-Set SPACE = SPACE/2 decrements counter SPACE end of while loop in step 211-Return takes control back to calling function