Motivated by an application in network security, we investigate the following
"linear" case of Directed Mutlicut. Let G be a directed graph which includes
some distinguished vertices t1,…,tk. What is the size of the
smallest edge cut which eliminates all paths from ti to tj for all i<j? We show that this problem is fixed-parameter tractable when parametrized in
the cutset size p via an algorithm running in O(4ppn4) time.Comment: 12 pages, 1 figur