lists and arrays revisited simple lists and arrays are the right tool for the many applications other situations require support for operations that cannot be implemented efficiently by the standard list representations of this presents advanced implementations for lists and arrays that overcome some of the problems of simple linked list and contiguous array representations wide range of topics are coveredwhose unifying thread is that the data structures are all listor array-like this should also serve to reinforce the concept of logical representation versus physical implementationas some of the "listimplementations have quite different organizations internally section describes series of representations for multilistswhich are lists that may contain sublists section discusses representations for implementing sparse matriceslarge matrices where most of the elements have zero values section discusses memory management techniqueswhich are essentially way of allocating variable-length sections from large array multilists recall from that list is finiteordered sequence of items of the form hx xn- where > we can represent the empty list by null or hi in we assumed that all list elements had the same data type in this sectionwe extend the definition of lists to allow elements to be arbitrary in nature in generallist elements are one of two types an atomwhich is data record of some type such as numbersymbolor string another listwhich is called sublist