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Approximation algorithms for dynamic storage allocation

  • Jordan Gergov
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 1136)

Abstract

We present a new O(n log n)-time 5-approximation algorithm for the NP-hard dynamic storage allocation problem (DSA). The two previous approximation algorithms for DSA are based on on-line coloring of interval graphs and have approximation ratios of 6 and 80 [6, 7, 16]. Our result gives an affirmative answer to the important open question of whether the approximation ratio of DSA can be improved below the bound implied by on-line coloring of interval graphs [7, 16]. Our approach is based on the novel concept of a 2-allocation and on the design of an efficient transformation of a 2-allocation to an at most 5/2 times larger memory allocation.

For the NP-hard variant of DSA with only two sizes of blocks allowed, we give a simpler 2-approximation algorithm. Further, by means of a tighter analysis of the widely used First Fit strategy, we show how the competitive ratio of on-line DSA can be improved to Θ(max{1, log(nk/M)}) where M, k, and n are upper bounds on the maximum number of simultaneously occupied cells, the maximum number of blocks simultaneously in the storage, and the maximum size of a block.

Keywords

Approximation Ratio Competitive Ratio Intersection Graph Interval Graph Decomposition Tree 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Springer-Verlag Berlin Heidelberg 1996

Authors and Affiliations

  • Jordan Gergov
    • 1
  1. 1.Max-Planck-Institut für InformatikSaarbrückenGermany

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