def test_dijkstra(self):
graph = [[(2, 1), (5, 2)], [(2, 0), (4, 2), (6, 3), (10, 4)],
[(5, 0), (4, 1), (2, 3)], [(2, 2), (6, 1), (1, 5)],
[(10, 1), (3, 5), (5, 6)], [(1, 3), (3, 4), (9, 6)],
[(5, 4), (9, 5)]]
djk = Dijkstra()
actual = djk.dijkstra(graph, 0)
expected = [0, 2, 5, 7, 11, 8, 16]
assert actual == expected
actual = djk.dijkstra(graph, 0, 6)
expected = [0, 2, 3, 5, 4, 6]
assert actual == expected
def johnson(network):
"""
Calculates the shortest path using Johnson's algorithm
Parameters
----------
src : str, int
An arbitrary node that does not exist in the STN.
Returns
-------
distance_matrix : List[List[int]]
A 2-D list representing the shortest distances between all the nodes
"""
distance_matrix = [[] for x in range(network.length)]
potential_function = BellmanFord.bellman_ford(network)
if not potential_function:
return False
for node_idx in range(network.length):
distance_matrix[node_idx] = Dijkstra.dijkstra(
network, node_idx, potential_function=potential_function)
if network.flag:
network.flag = False
# network.distance_matrix = distance_matrix
return distance_matrix
def dijkstra(network, src, succ_direction=True, potential_function=False):
return Dijkstra.dijkstra(network, src, succ_direction, potential_function)
