WALCOM: Algorithms and Computation
17th International Conference and Workshops, WALCOM 2023, Hsinchu, Taiwan, March 22–24, 2023, Proceedings
Recognizing When a Preference System is Close to Admitting a Master List
Ildikó Schlotter
Part of the Lecture Notes in Computer Science book series (LNCS,volume 13973)
Abstract
A preference system I is an undirected graph where vertices have preferences over their neighbors, and I admits a master list if all preferences can be derived from a single ordering over all vertices. We study the problem of deciding whether a given preference system I is close to admitting a master list based on three different distance measures. We determine the computational complexity of the following questions: can I be modified by (i) k swaps in the preferences, (ii) k edge deletions, or (iii) k vertex deletions so that the resulting instance admits a master list? We investigate these problems in detail from the viewpoint of parameterized complexity and of approximation. We also present two applications related to stable and popular matchings.