class TestGraph(unittest.TestCase): def setUp(self): self.undirected = UndirectedGraph() self.undirected.add_edge(1, 2, 2) self.undirected.add_edge(1, 3, 6) self.undirected.add_edge(2, 3, 3) self.undirected.add_edge(2, 4, 1) self.undirected.add_edge(3, 4, 1) self.undirected.add_edge(3, 5, 4) self.undirected.add_edge(4, 5, 6) self.directed = DirectedGraph() self.directed.add_edge(1, 2, 2) self.directed.add_edge(1, 3, 6) self.directed.add_edge(2, 3, 3) self.directed.add_edge(2, 4, 1) self.directed.add_edge(3, 4, 1) self.directed.add_edge(3, 5, 4) self.directed.add_edge(4, 5, 6) def test_get_edges(self): assert self.undirected.get_all_edges() == self.directed.get_all_edges() assert self.undirected.get_vertices() == self.directed.get_vertices() def test_directed_graph(self): assert len(self.directed.get_successive_vertices(4)) == 1 assert len(self.undirected.get_successive_vertices(4)) == 3 assert self.undirected.edge_exists(4, 3) assert not self.directed.edge_exists(4, 3) self.directed.delete_edge(4, 3) self.undirected.delete_edge(4, 3) assert len(self.directed.get_all_edges()) == len(self.undirected.get_all_edges()) + 1 def test_undirected_graph(self): g = UndirectedGraph()
class TestGraph(unittest.TestCase): def setUp(self): self.undirected = UndirectedGraph() self.undirected.add_edge(1, 2, 2) self.undirected.add_edge(1, 3, 6) self.undirected.add_edge(2, 3, 3) self.undirected.add_edge(2, 4, 1) self.undirected.add_edge(3, 4, 1) self.undirected.add_edge(3, 5, 4) self.undirected.add_edge(4, 5, 6) self.directed = DirectedGraph() self.directed.add_edge(1, 2, 2) self.directed.add_edge(1, 3, 6) self.directed.add_edge(2, 3, 3) self.directed.add_edge(2, 4, 1) self.directed.add_edge(3, 4, 1) self.directed.add_edge(3, 5, 4) self.directed.add_edge(4, 5, 6) def test_get_edges(self): assert self.undirected.get_all_edges() == self.directed.get_all_edges() assert self.undirected.get_vertices() == self.directed.get_vertices() def test_directed_graph(self): assert len(self.directed.get_successive_vertices(4)) == 1 assert len(self.undirected.get_successive_vertices(4)) == 3 assert self.undirected.edge_exists(4, 3) assert not self.directed.edge_exists(4, 3) self.directed.delete_edge(4, 3) self.undirected.delete_edge(4, 3) assert len(self.directed.get_all_edges()) == len( self.undirected.get_all_edges()) + 1 def test_undirected_graph(self): g = UndirectedGraph()
def contains_cycle(graph: UndirectedGraph) -> bool: """ Simple breadth first cycle detection for Undirected graphs """ graph = copy.deepcopy(graph) # type: Graph visited_nodes = set() queue = Queue() queue.enqueue(graph.get_vertices()[0]) while not queue.is_empty(): vertex = queue.dequeue() for neighbour in graph.get_successive_vertices(vertex): if neighbour in visited_nodes: return True visited_nodes.add(neighbour) queue.enqueue(neighbour) graph.delete_edge(vertex, neighbour) return False