TY - GEN
T1 - How hard is it to satisfy (Almost) all roommates?
AU - Chen, Jiehua
AU - Hermelin, Danny
AU - Sorge, Manuel
AU - Yedidsion, Harel
N1 - Publisher Copyright: © Jiehua Chen, Danny Hermelin, Manuel Sorge, and Harel Yedidsion;.
PY - 2018/7/1
Y1 - 2018/7/1
N2 - The classic Stable Roommates problem (the non-bipartite generalization of the well-known Stable Marriage problem) asks whether there is a stable matching for a given set of agents, i.e. a partitioning of the agents into disjoint pairs such that no two agents induce a blocking pair. Herein, each agent has a preference list denoting who it prefers to have as a partner, and two agents are blocking if they prefer to be with each other rather than with their assigned partners. Since stable matchings may not be unique, we study an NP-hard optimization variant of Stable Roommates, called Egal Stable Roommates, which seeks to find a stable matching with a minimum egalitarian cost γ, i.e. the sum of the dissatisfaction of the agents is minimum. The dissatisfaction of an agent is the number of agents that this agent prefers over its partner if it is matched; otherwise it is the length of its preference list. We also study almost stable matchings, called Min-Block-Pair Stable Roommates, which seeks to find a matching with a minimum number β of blocking pairs. Our main result is that Egal Stable Roommates parameterized by γ is fixed-parameter tractable, while Min-Block-Pair Stable Roommates parameterized by β is W[1]-hard, even if the length of each preference list is at most five.
AB - The classic Stable Roommates problem (the non-bipartite generalization of the well-known Stable Marriage problem) asks whether there is a stable matching for a given set of agents, i.e. a partitioning of the agents into disjoint pairs such that no two agents induce a blocking pair. Herein, each agent has a preference list denoting who it prefers to have as a partner, and two agents are blocking if they prefer to be with each other rather than with their assigned partners. Since stable matchings may not be unique, we study an NP-hard optimization variant of Stable Roommates, called Egal Stable Roommates, which seeks to find a stable matching with a minimum egalitarian cost γ, i.e. the sum of the dissatisfaction of the agents is minimum. The dissatisfaction of an agent is the number of agents that this agent prefers over its partner if it is matched; otherwise it is the length of its preference list. We also study almost stable matchings, called Min-Block-Pair Stable Roommates, which seeks to find a matching with a minimum number β of blocking pairs. Our main result is that Egal Stable Roommates parameterized by γ is fixed-parameter tractable, while Min-Block-Pair Stable Roommates parameterized by β is W[1]-hard, even if the length of each preference list is at most five.
KW - Analysis and algorithmics
KW - Data reduction rules
KW - Kernelizations
KW - NP-hard problems
KW - Parameterized complexity
UR - http://www.scopus.com/inward/record.url?scp=85049780267&partnerID=8YFLogxK
U2 - https://doi.org/10.4230/LIPIcs.ICALP.2018.35
DO - https://doi.org/10.4230/LIPIcs.ICALP.2018.35
M3 - Conference contribution
T3 - Leibniz International Proceedings in Informatics, LIPIcs
BT - 45th International Colloquium on Automata, Languages, and Programming, ICALP 2018
A2 - Kaklamanis, Christos
A2 - Marx, Daniel
A2 - Chatzigiannakis, Ioannis
A2 - Sannella, Donald
PB - Schloss Dagstuhl- Leibniz-Zentrum fur Informatik GmbH, Dagstuhl Publishing
T2 - 45th International Colloquium on Automata, Languages, and Programming, ICALP 2018
Y2 - 9 July 2018 through 13 July 2018
ER -