class TestUndirectedGraphMethods(unittest.TestCase):
def setUp(self):
self.graph = UndirectedGraph()
self.filled_graph = UndirectedGraph()
for i in range(6):
self.filled_graph.add_vertex(i + 1)
self.filled_graph.add_edge(1, 2)
self.filled_graph.add_edge(1, 4)
self.filled_graph.add_edge(2, 4)
self.filled_graph.add_edge(2, 3)
self.filled_graph.add_edge(4, 3)
self.filled_graph.add_edge(3, 6)
self.filled_graph.add_edge(4, 5)
self.filled_graph.add_edge(5, 6)
def test_adjacent(self):
# Edge does exist.
self.assertTrue(self.filled_graph.adjacent(1, 2))
# Edge does not exist.
self.assertFalse(self.filled_graph.adjacent(1, 3))
# Vertices to test do not exist.
self.assertFalse(self.filled_graph.adjacent(5, 8))
def test_neighbors(self):
self.assertCountEqual(self.filled_graph.neighbors(4), [1, 2, 3, 5])
self.assertCountEqual(self.filled_graph.neighbors(6), [3, 5])
self.assertEqual(self.filled_graph.neighbors(199), [])
def test_add_vertex(self):
old_len = len(self.graph)
self.graph.add_vertex(0)
self.assertEqual(len(self.graph), old_len + 1)
def test_remove_vertex(self):
# Remove a vertex that exists and verify its neighbors are updated.
target = 6
old_len = len(self.filled_graph)
self.filled_graph.remove_vertex(target)
self.assertEqual(len(self.filled_graph), old_len - 1)
self.assertNotIn(target, self.filled_graph.vertices)
self.assertNotIn(target, self.filled_graph.neighbors(3))
self.assertNotIn(target, self.filled_graph.neighbors(5))
# Attempt to remove a vertex that doesn't exist.
target = 100
old_len = len(self.filled_graph)
self.filled_graph.remove_vertex(target)
self.assertEqual(len(self.filled_graph), old_len)
self.assertNotIn(target, self.filled_graph.vertices)
def test_add_edge(self):
# Add edge between existing vertices.
self.assertFalse(self.filled_graph.adjacent(2, 6))
self.filled_graph.add_edge(2, 6)
self.assertTrue(self.filled_graph.adjacent(2, 6))
# Attempt to add edge to vertex that doesn't exist.
self.filled_graph.add_edge(2, 100)
self.assertNotIn(100, self.filled_graph.neighbors(2))
def test_remove_edge(self):
# Remove existing edge.
self.assertIn(3, self.filled_graph.neighbors(6))
self.filled_graph.remove_edge(3, 6)
self.assertNotIn(3, self.filled_graph.neighbors(6))
# Attempt to remove non-existing edge.
self.assertNotIn(1, self.filled_graph.neighbors(5))
self.filled_graph.remove_edge(1, 5)
self.assertNotIn(1, self.filled_graph.neighbors(5))
print("\nRemoving B -> D ...")
g.remove_edge('B', 'D')
print("\nEdges:")
g.print_edges()
print("\nPaths from A to D:")
g.print_paths('A', 'D')
print("\n\n***Undirected graph***")
u = UndirectedGraph()
u.add_vertex('A')
u.add_vertex('A')
u.add_vertex('B')
u.add_vertex('C')
print("\nVertices:", u.vertices())
u.add_edge('A', 'B')
u.add_edge('B', 'C')
u.add_edge('C', 'D')
u.add_edge('C', 'B')
u.add_edge('B', 'D')
u.add_edge('D', 'A')
print("\nEdges:")
u.print_edges()
