def test_can_add_multiple_edges_between_two_vertices(self):
graph = UndirectedGraph()
graph.add_edge(0, 1, 1)
graph.add_edge(0, 1, 2)
adjacency_list = graph.get_adjacency_list()
self.assertEqual(2, len(adjacency_list))
self.assertEqual(2, len(adjacency_list[0]))
self.assertListEqual([0, 0],
sorted(map(lambda e: e.start, adjacency_list[0])))
self.assertListEqual([1, 1],
sorted(map(lambda e: e.end, adjacency_list[0])))
self.assertListEqual([1, 2],
sorted(map(lambda e: e.weight,
adjacency_list[0])))
self.assertEqual(2, len(adjacency_list[1]))
self.assertListEqual([1, 1],
sorted(map(lambda e: e.start, adjacency_list[1])))
self.assertListEqual([0, 0],
sorted(map(lambda e: e.end, adjacency_list[1])))
self.assertListEqual([1, 2],
sorted(map(lambda e: e.weight,
adjacency_list[1])))
edges = graph.get_edges()
self.assertEqual(4, len(edges))
self.assertListEqual([0, 0, 1, 1], sorted(map(lambda e: e.start,
edges)))
self.assertListEqual([0, 0, 1, 1], sorted(map(lambda e: e.end, edges)))
self.assertListEqual([1, 1, 2, 2],
sorted(map(lambda e: e.weight, edges)))
def count_number_of_road_forks(field):
"""
Returns number of times you are able to move in more
than one direction by a given forest
:param field: Array of strings that represent forest
:return: number of road forks
"""
graph = UndirectedGraph()
start = None
end = None
height = len(field)
width = len(field[0])
for i, row in enumerate(field):
for j, symbol in enumerate(row):
if symbol == 'X':
continue
index = __linear_index(i, j, width)
if symbol == 'M':
start = index
if symbol == '*':
end = index
if __can_go_to(i - 1, j, height, width):
if field[i - 1][j] != 'X':
neighbor_index = __linear_index(i - 1, j, width)
graph.add_edge(neighbor_index, index, 1)
if __can_go_to(i, j - 1, height, width):
if field[i][j - 1] != 'X':
neighbor_index = __linear_index(i, j - 1, width)
graph.add_edge(neighbor_index, index, 1)
path = dijkstra_path(graph, start, end)
fork_count = 1 if len(graph.get_edges(start)) > 1 else 0
for vertex in path[1:-1]:
if len(graph.get_edges(vertex)) - 1 > 1:
fork_count += 1
return fork_count
def test_adding_single_edge_produces_two_directed_edges(self):
graph = UndirectedGraph()
graph.add_edge(0, 1, 1)
adjacency_list = graph.get_adjacency_list()
self.assertEqual(2, len(adjacency_list))
self.assertEqual(1, len(adjacency_list[0]))
self.assertEqual(0, adjacency_list[0][0].start)
self.assertEqual(1, adjacency_list[0][0].end)
self.assertEqual(1, adjacency_list[0][0].weight)
self.assertEqual(1, len(adjacency_list[1]))
self.assertEqual(1, adjacency_list[1][0].start)
self.assertEqual(0, adjacency_list[1][0].end)
self.assertEqual(1, adjacency_list[1][0].weight)
edges = graph.get_edges()
self.assertEqual(2, len(edges))
self.assertListEqual([0, 1], sorted(map(lambda e: e.start, edges)))
self.assertListEqual([0, 1], sorted(map(lambda e: e.end, edges)))
self.assertListEqual([1, 1], sorted(map(lambda e: e.weight, edges)))
def test_graph_is_empty_by_default(self):
graph = UndirectedGraph()
self.assertEqual(0, len(graph.get_adjacency_list()))
self.assertEqual(0, len(graph.get_edges()))
