linked lists adts as design tool the adt concept is useful aid in the software design process if you need to store datastart by considering the operations that need to be performed on that data do you need access to the last item insertedthe first onean item with specified keyan item in certain positionanswering such questions leads to the definition of an adt only after the adt is completely defined should you worry about the details of how to represent the data and how to code the methods that access the data by decoupling the specification of the adt from the implementation detailsyou can simplify the design process you also make it easier to change the implementation at some future time if user relates only to the adt interfaceyou should be able to change the implementation without "breakingthe user' code of courseonce the adt has been designedthe underlying data structure must be carefully chosen to make the specified operations as efficient as possible if you need random access to element nfor examplethe linked-list representation isn' so good because random access isn' an efficient operation for linked list you' be better off with an array note remember that the adt concept is only conceptual tool data storage structures are not divided cleanly into some that are adts and some that are used to implement adts linked listfor exampledoesn' need to be wrapped in list interface to be usefulit can act as an adt on its ownor it can be used to implement another data type such as queue linked list can be implemented using an arrayand an array-type structure can be implemented using linked list what' an adt and what' more basic structure must be determined in given context sorted lists in the linked lists we've seen thus farthere was no requirement that data be stored in order howeverfor certain applications it' useful to maintain the data in sorted order within the list list with this characteristic is called sorted list in sorted listthe items are arranged in sorted order by key value deletion is often limited to the smallest (or the largestitem in the listwhich is at the start of the listalthough sometimes find(and delete(methodswhich search through the list for specified linksare used as well in general you can use sorted list in most situations in which you use sorted array the advantages of sorted list over sorted array are speed of insertion (because elements don' need to be movedand the fact that list can expand to fill