English

Approximation Algorithms for Restricted Cycle Covers Based on Cycle Decompositions

Data Structures and Algorithms 2007-05-23 v4 Computational Complexity Discrete Mathematics

Abstract

A cycle cover of a graph is a set of cycles such that every vertex is part of exactly one cycle. An L-cycle cover is a cycle cover in which the length of every cycle is in the set L. The weight of a cycle cover of an edge-weighted graph is the sum of the weights of its edges. We come close to settling the complexity and approximability of computing L-cycle covers. On the one hand, we show that for almost all L, computing L-cycle covers of maximum weight in directed and undirected graphs is APX-hard and NP-hard. Most of our hardness results hold even if the edge weights are restricted to zero and one. On the other hand, we show that the problem of computing L-cycle covers of maximum weight can be approximated within a factor of 2 for undirected graphs and within a factor of 8/3 in the case of directed graphs. This holds for arbitrary sets L.

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Cite

@article{arxiv.cs/0604020,
  title  = {Approximation Algorithms for Restricted Cycle Covers Based on Cycle Decompositions},
  author = {Bodo Manthey},
  journal= {arXiv preprint arXiv:cs/0604020},
  year   = {2007}
}

Comments

This paper has been joint with "On Approximating Restricted Cycle Covers" (cs.CC/0504038). Please refer to that paper. The paper "Approximation Algorithms for Restricted Cycle Covers Based on Cycle Decompositions" is now obsolete