@Test
public void testTransitiveClosure() {
Graph<String, String> graph = new AdjacencyList<String, String>();
graph.addEdge("A", "B");
graph.addEdge("B", "C");
graph.addEdge("D", "C");
// A -> B
// |
// v
// C <- D
Graph<String, String> closure = GraphHelper.transitiveClosure(graph);
// A ->B
// \ |
// \ v
// _|C <- D
assertEquals(4, closure.getEdgeSet().size());
assertTrue(closure.hasEdge("A", "B"));
assertTrue(closure.hasEdge("B", "C"));
assertTrue(closure.hasEdge("A", "C"));
assertTrue(closure.hasEdge("D", "C"));
assertTrue(!closure.hasEdge("A", "D"));
assertTrue(!closure.hasEdge("B", "D"));
assertTrue(!closure.hasEdge("C", "D"));
assertEquals(3, graph.getEdgeSet().size());
assertTrue(graph.hasEdge("A", "B"));
assertTrue(graph.hasEdge("B", "C"));
assertTrue(!graph.hasEdge("A", "C"));
assertTrue(graph.hasEdge("D", "C"));
}
@Test
public void testTransitiveClosure2() {
Graph<String, String> graph = new AdjacencyList<String, String>();
graph.addEdge("A", "B");
graph.addEdge("B", "C");
graph.addEdge("C", "D");
graph.addEdge("D", "E");
// A D -> E
// \ /
// B-->C
Graph<String, String> closure = GraphHelper.transitiveClosure(graph);
assertEquals(10, closure.getEdgeSet().size());
assertTrue(closure.hasEdge("A", "B"));
assertTrue(closure.hasEdge("A", "C"));
assertTrue(closure.hasEdge("A", "D"));
assertTrue(closure.hasEdge("A", "E"));
assertTrue(closure.hasEdge("B", "C"));
assertTrue(closure.hasEdge("B", "D"));
assertTrue(closure.hasEdge("B", "E"));
assertTrue(closure.hasEdge("C", "D"));
assertTrue(closure.hasEdge("C", "E"));
assertTrue(closure.hasEdge("D", "E"));
assertTrue(!closure.hasEdge("E", "A"));
assertTrue(!closure.hasEdge("E", "B"));
assertTrue(!closure.hasEdge("E", "C"));
assertTrue(!closure.hasEdge("E", "D"));
assertTrue(!closure.hasEdge("D", "A"));
assertTrue(!closure.hasEdge("D", "B"));
assertTrue(!closure.hasEdge("D", "C"));
assertTrue(!closure.hasEdge("C", "B"));
assertTrue(!closure.hasEdge("C", "A"));
assertTrue(!closure.hasEdge("B", "A"));
}