A specialised binary constraint for the stable marriage problem

Abstract

We present a specialised binary constraint for the stable marriage problem. This constraint acts between a pair of integer variables where the domains of those variables represent preferences. Our constraint enforces stability and disallows bigamy. For a stable marriage instance with n men and women we require n2 of these constraints, and the complexity of enforcing arc-consistency is O(n3). Although this is non-optimal, empirical evidence suggests that in practical terms our encoding significantly outperforms the optimal encoding given in [7] in both space and time