Hardness results and approximation algorithms for identifying codes and locating-dominating codes in graphs

Authors

  • Sylvain Gravier CNRS - Institut Fourier, ERT Maths à Modeler
  • Ralf Klasing LaBRI - Université Bordeaux 1 - CNRS
  • Julien Moncel INPG-ENSGI, Laboratoire G-SCOP

Keywords:

approximation algorithms, approximation hardness, identifying codes, locating-dominating codes, fault tolerance, domination problems, combinatorial optimization, graph algorithms.

Abstract

In a graph G = (V, E), an identifying code of G (resp. a locating-dominating code of G) is a subset of vertices C ⊆ V such that N[v] ∩ C ≠ ∅ for all v ∈ V , and N[u] ∩ C ≠ N[v] ∩ C for all u ≠ v, u, v ∈ V (resp. u, v ∈ V [integerdivide] C), where N[u] denotes the closed neighbourhood of v, that is N[u] = N(u) ∪ {u}. These codes model fault-detection problems in multiprocessor systems and are also used for designing location-detection schemes in wireless sensor networks. We give here simple reductions which improve results of the paper [I. Charon, O. Hudry, A. Lobstein, Minimizing the Size of an Identifying or Locating-Dominating Code in a Graph is NP-hard, Theoretical Computer Science 290(3) (2003), 2109-2120], and we show that minimizing the size of an identifying code or a locating-dominating code in a graph is APX-hard, even when restricted to graphs of bounded degree. Additionally, we give approximation algorithms for both problems with approximation ratio O(ln |V |) for general graphs and O(1) in the case where the degree of the graph is bounded by a constant.

Author Biographies

Sylvain Gravier, CNRS - Institut Fourier, ERT Maths à Modeler

Chargé de recherche CNRS

Ralf Klasing, LaBRI - Université Bordeaux 1 - CNRS

Chargé de recherche CNRS

Julien Moncel, INPG-ENSGI, Laboratoire G-SCOP

Maître de conférences

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Published

2008-03-25

How to Cite

Gravier, S., Klasing, R., & Moncel, J. (2008). Hardness results and approximation algorithms for identifying codes and locating-dominating codes in graphs. Algorithmic Operations Research, 3(1). Retrieved from https://journals.lib.unb.ca/index.php/AOR/article/view/2808

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Articles