A novel algorithm for list accessing problem

Abstract

List accessing problem is seen as a self-organizing linear search problem. The dilemma is to access a sequence of requests from an unordered linear list such that the total cost is minimized. However, the unordered linear list may be reorganized at any time. The rationale behind such reorganization is to decrease the cost of forthcoming requests. But reorganization is not always decreasing the cost. The cost of request sequence can be reduced to devise an algorithm that minimizes the reorganization of the unsorted linear list. In this paper, we propose a novel algorithm called hash table based positioning (HTBP) for list accessing problem. The algorithm is based on the concept of hash table. We incorporate the reorganization costs in terms of pre-organization, displacement and post-organization cost. We perform extensive mathematical analysis on some special types of request sequence as well as random sequence and compare the results with a well-known list accessing algorithm called move-to-front. The experimental results show that the proposed algorithm outperforms than move-to-front algorithm.