Paper Info
Title
A constant factor approximation algorithm for reordering buffer management
Abstract
In the reordering buffer management problem (RBM) a sequence of n colored items enters a buffer with limited capacity k. When the buffer is full, one item is removed to the output sequence, making room for the next input item. This step is repeated until the input sequence is exhausted and the buffer is empty. The objective is to find a sequence of removals that minimizes the total number of color changes in the output sequence. The problem formalizes numerous applications in computer and production systems, and is known to be NP-hard. We give the first constant factor approximation guarantee for RBM. Our algorithm is based on an intricate \"rounding\" of the solution to an LP relaxation for RBM, so it also establishes a constant upper bound on the integrality gap of this relaxation. Our results improve upon the best previous bound of O(√ log k) of Adamaszek et al. (STOC 2011) that used different methods and gave an online algorithm. Our constant factor approximation beats the super-constant lower bounds on the competitive ratio given by Adamaszek et al. This is the first demonstration of a polynomial time offline algorithm for RBM that is provably better than any online algorithm.
Year
DOI
Venue
2012
10.5555/2627817.2627887
SODA
Keywords
DocType
Volume
algorithms,design,approximation,theory,sequencing and scheduling
Journal
abs/1202.4504
ISBN
Citations 
PageRank 
978-1-61197-251-1
8
0.49
References 
Authors
15
2
Name
Order
Citations
PageRank
Noa Avigdor-Elgrabli1544.48
Yuval Rabani22265274.98