Efficient algorithms for the problems of enumerating cuts by non-decreasing weights

Abstract

In this paper, we study the problems of enumerating cuts of a graph by non-decreasing weights. There are four problems, depending on whether the graph is directed or undirected, and on whether we consider all cuts of the graph or only s-t cuts for a given pair of vertices s,t. Efficient algorithms for these problems with Õ(n2m) delay between two successive outputs have been known since 1992, due to Vazirani and Yannakakis. In this paper, improved algorithms are presented. The delays of the presented algorithms are O (nm log(n2/m)). Vazirani and Yannakakis's algorithms have been used as basic subroutines in the solutions of many problems. Therefore, our improvement immediately reduces the running time of these solutions. For example, for the minimum k-cut problem, the upper bound is immediately reduced by a factor of Õ(n) for k=3,4,5,6. © 2009 Springer Science+Business Media, LLC.