Reducing off-line to on-line: An example and its applications
We study on-line versions of maximum weighted hereditary subgraph problems for which the instance is revealed in two clusters. We focus on the comparison of these on-line problems with their respective off-line versions. In [3], we have reduced on-line versions to the off-line ones in order to devis...
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| Format: | Article |
| Language: | English |
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University of Belgrade
2003-01-01
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| Series: | Yugoslav Journal of Operations Research |
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| Online Access: | http://www.doiserbia.nb.rs/img/doi/0354-0243/2003/0354-02430301003D.pdf |
| Summary: | We study on-line versions of maximum weighted hereditary subgraph problems for which the instance is revealed in two clusters. We focus on the comparison of these on-line problems with their respective off-line versions. In [3], we have reduced on-line versions to the off-line ones in order to devise competitive analysis for such problems. In this paper, we first devise hardness results pointing out that this previous analysis was tight. Then, we propose a process that allows, for a large class of hereditary problems, to transform an on-line algorithm into an off-line one with improvement of the guarantees. This result can be seen as an inverse version of our previous work. It brings to the fore a hardness gap between on-line and off-line versions of those problems. This result does not apply in the case of maximizing a k -colorable induced subgraph of a given graph. For this problem we point out that, contrary to the first case, the on-line version is almost as well approximated as the offline one. . |
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| ISSN: | 0354-0243 1820-743X |