Department of Applied Mathematics & Physics, Kyoto University

Technical Report 2019-002 (June 11, 2019)

A Polynomial-delay Algorithm for Enumerating Connectors under Various Connectivity Conditions
by Kazuya Haraguchi and Hiroshi Nagamochi

pdf File


We are given an instance (G,I,s) with a graph G=(V,E), a set I of items, and a function s from V to I. For a subset X of V, let G[X] denote the subgraph induced from G by X, and Item(X) denote the common item set over X. A subset X of V such that G[X] is connected is called a connector if, for any vertex $vin Vsetminus X$, G[X cup {v}] is not connected or Item(X cup {v}) is a proper subset of Item(X). In this paper, we present the first polynomial-delay algorithm for enumerating all connectors. For this, we first extend the problem of enumerating connectors to a general setting so that the connectivity condition on X in G can be specified in a more flexible way. We next design a new algorithm for enumerating all solutions in the general setting, which leads to a polynomial-delay algorithm for enumerating all connectors for several connectivity conditions on X in G, such as the biconnectivity of G[X] or the k-edge-connectivity among vertices in X in G.