CS 280 Data Structures Professor John Peterson

Programming Let’s look at my code. This will be available in the wiki. There is a short assignment due on Friday – add more sort methods to your program (selection and bubble)

Properties of Sort Algorithms Size of algorithm Performance on small datasets Performance on large datasets Nearly sorted inputs (best case?) Stability – can the order of elements with equal keys change? Memory usage – do you need more than a constant amount beyond the array? Online – can the algorithm do anything before all data is available?

Insertion Sort Properties What properties are of interest here? insertionSort(array A) for i <- 1 to length[A]-1 do value <- A[i] j <- i-1 while j >= 0 and A[j] > value do A[j + 1] = A[j]; j <- j-1 A[j+1] <- value t

Other Properties From Wikipedia: Efficient on (quite) small data sets Efficient on data sets which are already substantially sorted: it runs in O(n + d) time, where d is the number of inversionsinversions More efficient in practice than most other simple O(n 2 ) algorithms such as selection sort or bubble sort: the average time is n 2 /4 and it is linear in the best caseOselection sortbubble sort Stable (does not change the relative order of elements with equal keys)Stable In-place (only requires a constant amount O(1) of extra memory space)In-place It is an online algorithm, in that it can sort a list as it receives it.online algorithm