There are many existing well known cost models for the list accessing
problem. The standard cost model developed by Sleator and Tarjan is most widely
used. In this paper, we have made a comprehensive study of the existing cost
models and proposed a new cost model for the list accessing problem. In our
proposed cost model, for calculating the processing cost of request sequence
using a singly linked list, we consider the access cost, matching cost and
replacement cost. The cost of processing a request sequence is the sum of
access cost, matching cost and replacement cost.
List Accessing Problem is a well studied research problem in the context of
linear search. Input to the list accessing problem is an unsorted linear list
of distinct elements along with a sequence of requests, where each request is
an access operation on an element of the list. A list accessing algorithm
reorganizes the list while processing a request sequence on the list in order
to minimize the access cost.
Cryptographic hash functions for calculating the message digest of a message
has been in practical use as an effective measure to maintain message integrity
since a few decades. This message digest is unique, irreversible and avoids all
types of collisions for any given input string. The message digest calculated
from this algorithm is propagated in the communication medium along with the
original message from the sender side and on the receiver side integrity of the
message can be verified by recalculating the message digest of the received
message and comparing the two digest values.
The main objective of this survey is to present the important theoretical and
experimental results contributed till date in the area of online algorithms for
the self organizing sequential search problem, also popularly known as the List
Update Problem(LUP) in a chronological way. The survey includes competitiveness
results of deterministic and randomized online algorithms and complexity
results of optimal off line algorithms for the list update problem.