Abstract
We consider instances of the classical stable marriage problem in which persons may include ties in their preference lists. We show that, in such a setting, strong lower bounds hold for the approximability of each of the problems of finding an egalitarian, minimum regret and sex-equal stable matching. We also consider stable marriage instances in which persons may express unacceptable partners in addition to ties. In this setting, we prove that there are constants δ, δ′ such that each of the problems of approximating a maximum and minimum cardinality stable matching within factors of δ, δ′ (respectively) is NP-hard, under strong restrictions. We also give an approximation algorithm for both problems that has a performance guarantee expressible in terms of the number of lists with ties. This significantly improves on the best-known previous performance guarantee, for the case that the ties are sparse. Our results have applications to large-scale centralized matching schemes.
| Original language | English |
|---|---|
| Pages (from-to) | 431-447 |
| Number of pages | 17 |
| Journal | Theoretical Computer Science |
| Volume | 306 |
| Issue number | 1-3 |
| DOIs | |
| Publication status | Published - 5 Sept 2003 |
Bibliographical note
Funding Information: Keywords: Stable marriage problem; Ties; Unacceptable partners; Inapproximability results; Approximation algorithm An earlier version of a part of this paper appeared in [8]. ∗Corresponding author. Tel.: +44-141-330-2794; fax: +44-141-330-4913. E-mail addresses: [email protected] (M.M. Halldo'rsson), [email protected] (R.W. Irving), iwama@kuis. kyoto-u.ac.jp (K. Iwama), [email protected] (D.F. Manlove), [email protected] (S. Miyazaki), [email protected] (Y. Morita), [email protected] (S. Scott). 1Supported in part by Scienti9c Research Grant, Ministry of Japan, 13480081. 2Supported by award NUF-NAL-02 from the NuLeld Foundation and grant GR/R84597/01 from the Engineering and Physical Sciences Research Council.Other keywords
- Approximation algorithm
- Inapproximability results
- Stable marriage problem
- Ties
- Unacceptable partners