Abstract:
|
We consider the list access problem and show that one questionable
assumption in the original cost model presented by Sleator and Tarjan
(Amortized Efficiency of List Update and Paging Rules, CACM,
28(2):202-208, 1985)
and subsequent literature allowed for several
competitiveness results of the move-to-front rule (MTF). We
present an off-line algorithm for the
list access problem and prove that, under a more realistic cost model,
no on-line algorithm can be c-competitive for any constant
c, MTF included. |