Fixed-parameter tractability of multicut parameterized by the size of the cutset
arXiv:1010.3633
Abstract
Given an undirected graph , a collection of pairs of vertices, and an integer , the Edge Multicut problem ask if there is a set of at most edges such that the removal of disconnects every from the corresponding . Vertex Multicut is the analogous problem where is a set of at most vertices. Our main result is that both problems can be solved in time , i.e., fixed-parameter tractable parameterized by the size of the cutset in the solution. By contrast, it is unlikely that an algorithm with running time of the form exists for the directed version of the problem, as we show it to be W[1]-hard parameterized by the size of the cutset.