def test_bfs_subgraph_does_not_reverse_egde_direction(self):
graph = Graph()
graph.add_node('A')
graph.add_node('B')
graph.add_node('C')
graph.add_edge('A', 'B')
graph.add_edge('B', 'C')
whole_graph = graph.forw_topo_sort()
subgraph_backward = graph.back_bfs_subgraph('C')
subgraph_backward = subgraph_backward.forw_topo_sort()
self.assertEquals(whole_graph, subgraph_backward)
subgraph_forward = graph.forw_bfs_subgraph('A')
subgraph_forward = subgraph_forward.forw_topo_sort()
self.assertEquals(whole_graph, subgraph_forward)
def test_bfs_subgraph(self):
graph = Graph()
graph.add_edge(1, 2)
graph.add_edge(1, 4)
graph.add_edge(2, 4)
graph.add_edge(4, 8)
graph.add_edge(4, 9)
graph.add_edge(4, 10)
graph.add_edge(8, 10)
subgraph = graph.forw_bfs_subgraph(10)
self.assertTrue(isinstance(subgraph, Graph))
self.assertEqual(subgraph.number_of_nodes(), 1)
self.assertTrue(10 in subgraph)
self.assertEqual(subgraph.number_of_edges(), 0)
subgraph = graph.forw_bfs_subgraph(4)
self.assertTrue(isinstance(subgraph, Graph))
self.assertEqual(subgraph.number_of_nodes(), 4)
self.assertTrue(4 in subgraph)
self.assertTrue(8 in subgraph)
self.assertTrue(9 in subgraph)
self.assertTrue(10 in subgraph)
self.assertEqual(subgraph.number_of_edges(), 4)
e = subgraph.edge_by_node(4, 8)
e = subgraph.edge_by_node(4, 9)
e = subgraph.edge_by_node(4, 10)
e = subgraph.edge_by_node(8, 10)
# same graph as before, but switch around
# edges. This results in the same test results
# but now for back_bfs_subgraph rather than
# forw_bfs_subgraph
graph = Graph()
graph.add_edge(2, 1)
graph.add_edge(4, 1)
graph.add_edge(4, 2)
graph.add_edge(8, 4)
graph.add_edge(9, 4)
graph.add_edge(10, 4)
graph.add_edge(10, 8)
subgraph = graph.back_bfs_subgraph(10)
self.assertTrue(isinstance(subgraph, Graph))
self.assertEqual(subgraph.number_of_nodes(), 1)
self.assertTrue(10 in subgraph)
self.assertEqual(subgraph.number_of_edges(), 0)
subgraph = graph.back_bfs_subgraph(4)
self.assertTrue(isinstance(subgraph, Graph))
self.assertEqual(subgraph.number_of_nodes(), 4)
self.assertTrue(4 in subgraph)
self.assertTrue(8 in subgraph)
self.assertTrue(9 in subgraph)
self.assertTrue(10 in subgraph)
self.assertEqual(subgraph.number_of_edges(), 4)
e = subgraph.edge_by_node(4, 8)
e = subgraph.edge_by_node(4, 9)
e = subgraph.edge_by_node(4, 10)
e = subgraph.edge_by_node(8, 10)
