title: Find set of nodes whose removal maximally reduces the transitive closure of the root
body: <p>I have a directed graph of up to 10,000 nodes. There's a root node from which the graph stems, i.e., it's connected to all of them. The . I need to efficiently figure out which 5 nodes I can delete that would reduce the transitive closure of the root node by the maximum possible. The transitive closure being the set of all nodes that are somehow reachable from the root through 1 or more edges. Any ideas?</p>