Simple linked lists were introduced in the last chapter. The utility of these can be extended considerably by adding a few new procedures and by allowing for the data type used to be easily changed.
Besides the various kinds of lists, certain other structures for data are also widely used. Sometimes these are just variations on the linked list theme, and sometimes they are not linear at all. While the subject of data structures in general is usually thought of as providing the material for an entire text, enough of the principles of ADTs have already been discussed here to allow these structures to be dealt with in a more succinct fashion than in the traditional course, and yet not lose any generality. Taken together with the discussions on algorithms in the previous chapter and the extensions in the next two, this material can itself provide the basis for an adequate replacement for the traditional data structures course.