Mercurial > repos > shellac > sam_consensus_v3
diff env/lib/python3.9/site-packages/networkx/algorithms/tests/test_simple_paths.py @ 0:4f3585e2f14b draft default tip
"planemo upload commit 60cee0fc7c0cda8592644e1aad72851dec82c959"
author | shellac |
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date | Mon, 22 Mar 2021 18:12:50 +0000 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/env/lib/python3.9/site-packages/networkx/algorithms/tests/test_simple_paths.py Mon Mar 22 18:12:50 2021 +0000 @@ -0,0 +1,764 @@ +import random + +import pytest + +import networkx as nx +from networkx import convert_node_labels_to_integers as cnlti +from networkx.algorithms.simple_paths import _bidirectional_dijkstra +from networkx.algorithms.simple_paths import _bidirectional_shortest_path +from networkx.utils import arbitrary_element +from networkx.utils import pairwise + + +class TestIsSimplePath: + """Unit tests for the + :func:`networkx.algorithms.simple_paths.is_simple_path` function. + + """ + + def test_empty_list(self): + """Tests that the empty list is not a valid path, since there + should be a one-to-one correspondence between paths as lists of + nodes and paths as lists of edges. + + """ + G = nx.trivial_graph() + assert not nx.is_simple_path(G, []) + + def test_trivial_path(self): + """Tests that the trivial path, a path of length one, is + considered a simple path in a graph. + + """ + G = nx.trivial_graph() + assert nx.is_simple_path(G, [0]) + + def test_trivial_nonpath(self): + """Tests that a list whose sole element is an object not in the + graph is not considered a simple path. + + """ + G = nx.trivial_graph() + assert not nx.is_simple_path(G, ["not a node"]) + + def test_simple_path(self): + G = nx.path_graph(2) + assert nx.is_simple_path(G, [0, 1]) + + def test_non_simple_path(self): + G = nx.path_graph(2) + assert not nx.is_simple_path(G, [0, 1, 0]) + + def test_cycle(self): + G = nx.cycle_graph(3) + assert not nx.is_simple_path(G, [0, 1, 2, 0]) + + def test_missing_node(self): + G = nx.path_graph(2) + assert not nx.is_simple_path(G, [0, 2]) + + def test_directed_path(self): + G = nx.DiGraph([(0, 1), (1, 2)]) + assert nx.is_simple_path(G, [0, 1, 2]) + + def test_directed_non_path(self): + G = nx.DiGraph([(0, 1), (1, 2)]) + assert not nx.is_simple_path(G, [2, 1, 0]) + + def test_directed_cycle(self): + G = nx.DiGraph([(0, 1), (1, 2), (2, 0)]) + assert not nx.is_simple_path(G, [0, 1, 2, 0]) + + def test_multigraph(self): + G = nx.MultiGraph([(0, 1), (0, 1)]) + assert nx.is_simple_path(G, [0, 1]) + + def test_multidigraph(self): + G = nx.MultiDiGraph([(0, 1), (0, 1), (1, 0), (1, 0)]) + assert nx.is_simple_path(G, [0, 1]) + + +# Tests for all_simple_paths +def test_all_simple_paths(): + G = nx.path_graph(4) + paths = nx.all_simple_paths(G, 0, 3) + assert {tuple(p) for p in paths} == {(0, 1, 2, 3)} + + +def test_all_simple_paths_with_two_targets_emits_two_paths(): + G = nx.path_graph(4) + G.add_edge(2, 4) + paths = nx.all_simple_paths(G, 0, [3, 4]) + assert {tuple(p) for p in paths} == {(0, 1, 2, 3), (0, 1, 2, 4)} + + +def test_digraph_all_simple_paths_with_two_targets_emits_two_paths(): + G = nx.path_graph(4, create_using=nx.DiGraph()) + G.add_edge(2, 4) + paths = nx.all_simple_paths(G, 0, [3, 4]) + assert {tuple(p) for p in paths} == {(0, 1, 2, 3), (0, 1, 2, 4)} + + +def test_all_simple_paths_with_two_targets_cutoff(): + G = nx.path_graph(4) + G.add_edge(2, 4) + paths = nx.all_simple_paths(G, 0, [3, 4], cutoff=3) + assert {tuple(p) for p in paths} == {(0, 1, 2, 3), (0, 1, 2, 4)} + + +def test_digraph_all_simple_paths_with_two_targets_cutoff(): + G = nx.path_graph(4, create_using=nx.DiGraph()) + G.add_edge(2, 4) + paths = nx.all_simple_paths(G, 0, [3, 4], cutoff=3) + assert {tuple(p) for p in paths} == {(0, 1, 2, 3), (0, 1, 2, 4)} + + +def test_all_simple_paths_with_two_targets_in_line_emits_two_paths(): + G = nx.path_graph(4) + paths = nx.all_simple_paths(G, 0, [2, 3]) + assert {tuple(p) for p in paths} == {(0, 1, 2), (0, 1, 2, 3)} + + +def test_all_simple_paths_ignores_cycle(): + G = nx.cycle_graph(3, create_using=nx.DiGraph()) + G.add_edge(1, 3) + paths = nx.all_simple_paths(G, 0, 3) + assert {tuple(p) for p in paths} == {(0, 1, 3)} + + +def test_all_simple_paths_with_two_targets_inside_cycle_emits_two_paths(): + G = nx.cycle_graph(3, create_using=nx.DiGraph()) + G.add_edge(1, 3) + paths = nx.all_simple_paths(G, 0, [2, 3]) + assert {tuple(p) for p in paths} == {(0, 1, 2), (0, 1, 3)} + + +def test_all_simple_paths_source_target(): + G = nx.path_graph(4) + paths = nx.all_simple_paths(G, 1, 1) + assert list(paths) == [] + + +def test_all_simple_paths_cutoff(): + G = nx.complete_graph(4) + paths = nx.all_simple_paths(G, 0, 1, cutoff=1) + assert {tuple(p) for p in paths} == {(0, 1)} + paths = nx.all_simple_paths(G, 0, 1, cutoff=2) + assert {tuple(p) for p in paths} == {(0, 1), (0, 2, 1), (0, 3, 1)} + + +def test_all_simple_paths_on_non_trivial_graph(): + """ you may need to draw this graph to make sure it is reasonable """ + G = nx.path_graph(5, create_using=nx.DiGraph()) + G.add_edges_from([(0, 5), (1, 5), (1, 3), (5, 4), (4, 2), (4, 3)]) + paths = nx.all_simple_paths(G, 1, [2, 3]) + assert {tuple(p) for p in paths} == { + (1, 2), + (1, 3, 4, 2), + (1, 5, 4, 2), + (1, 3), + (1, 2, 3), + (1, 5, 4, 3), + (1, 5, 4, 2, 3), + } + paths = nx.all_simple_paths(G, 1, [2, 3], cutoff=3) + assert {tuple(p) for p in paths} == { + (1, 2), + (1, 3, 4, 2), + (1, 5, 4, 2), + (1, 3), + (1, 2, 3), + (1, 5, 4, 3), + } + paths = nx.all_simple_paths(G, 1, [2, 3], cutoff=2) + assert {tuple(p) for p in paths} == {(1, 2), (1, 3), (1, 2, 3)} + + +def test_all_simple_paths_multigraph(): + G = nx.MultiGraph([(1, 2), (1, 2)]) + paths = nx.all_simple_paths(G, 1, 1) + assert list(paths) == [] + nx.add_path(G, [3, 1, 10, 2]) + paths = list(nx.all_simple_paths(G, 1, 2)) + assert len(paths) == 3 + assert {tuple(p) for p in paths} == {(1, 2), (1, 2), (1, 10, 2)} + + +def test_all_simple_paths_multigraph_with_cutoff(): + G = nx.MultiGraph([(1, 2), (1, 2), (1, 10), (10, 2)]) + paths = list(nx.all_simple_paths(G, 1, 2, cutoff=1)) + assert len(paths) == 2 + assert {tuple(p) for p in paths} == {(1, 2), (1, 2)} + + +def test_all_simple_paths_directed(): + G = nx.DiGraph() + nx.add_path(G, [1, 2, 3]) + nx.add_path(G, [3, 2, 1]) + paths = nx.all_simple_paths(G, 1, 3) + assert {tuple(p) for p in paths} == {(1, 2, 3)} + + +def test_all_simple_paths_empty(): + G = nx.path_graph(4) + paths = nx.all_simple_paths(G, 0, 3, cutoff=2) + assert list(paths) == [] + + +def test_all_simple_paths_corner_cases(): + assert list(nx.all_simple_paths(nx.empty_graph(2), 0, 0)) == [] + assert list(nx.all_simple_paths(nx.empty_graph(2), 0, 1)) == [] + assert list(nx.all_simple_paths(nx.path_graph(9), 0, 8, 0)) == [] + + +def hamiltonian_path(G, source): + source = arbitrary_element(G) + neighbors = set(G[source]) - {source} + n = len(G) + for target in neighbors: + for path in nx.all_simple_paths(G, source, target): + if len(path) == n: + yield path + + +def test_hamiltonian_path(): + from itertools import permutations + + G = nx.complete_graph(4) + paths = [list(p) for p in hamiltonian_path(G, 0)] + exact = [[0] + list(p) for p in permutations([1, 2, 3], 3)] + assert sorted(paths) == sorted(exact) + + +def test_cutoff_zero(): + G = nx.complete_graph(4) + paths = nx.all_simple_paths(G, 0, 3, cutoff=0) + assert list(list(p) for p in paths) == [] + paths = nx.all_simple_paths(nx.MultiGraph(G), 0, 3, cutoff=0) + assert list(list(p) for p in paths) == [] + + +def test_source_missing(): + with pytest.raises(nx.NodeNotFound): + G = nx.Graph() + nx.add_path(G, [1, 2, 3]) + list(nx.all_simple_paths(nx.MultiGraph(G), 0, 3)) + + +def test_target_missing(): + with pytest.raises(nx.NodeNotFound): + G = nx.Graph() + nx.add_path(G, [1, 2, 3]) + list(nx.all_simple_paths(nx.MultiGraph(G), 1, 4)) + + +# Tests for all_simple_edge_paths +def test_all_simple_edge_paths(): + G = nx.path_graph(4) + paths = nx.all_simple_edge_paths(G, 0, 3) + assert {tuple(p) for p in paths} == {((0, 1), (1, 2), (2, 3))} + + +def test_all_simple_edge_paths_with_two_targets_emits_two_paths(): + G = nx.path_graph(4) + G.add_edge(2, 4) + paths = nx.all_simple_edge_paths(G, 0, [3, 4]) + assert {tuple(p) for p in paths} == { + ((0, 1), (1, 2), (2, 3)), + ((0, 1), (1, 2), (2, 4)), + } + + +def test_digraph_all_simple_edge_paths_with_two_targets_emits_two_paths(): + G = nx.path_graph(4, create_using=nx.DiGraph()) + G.add_edge(2, 4) + paths = nx.all_simple_edge_paths(G, 0, [3, 4]) + assert {tuple(p) for p in paths} == { + ((0, 1), (1, 2), (2, 3)), + ((0, 1), (1, 2), (2, 4)), + } + + +def test_all_simple_edge_paths_with_two_targets_cutoff(): + G = nx.path_graph(4) + G.add_edge(2, 4) + paths = nx.all_simple_edge_paths(G, 0, [3, 4], cutoff=3) + assert {tuple(p) for p in paths} == { + ((0, 1), (1, 2), (2, 3)), + ((0, 1), (1, 2), (2, 4)), + } + + +def test_digraph_all_simple_edge_paths_with_two_targets_cutoff(): + G = nx.path_graph(4, create_using=nx.DiGraph()) + G.add_edge(2, 4) + paths = nx.all_simple_edge_paths(G, 0, [3, 4], cutoff=3) + assert {tuple(p) for p in paths} == { + ((0, 1), (1, 2), (2, 3)), + ((0, 1), (1, 2), (2, 4)), + } + + +def test_all_simple_edge_paths_with_two_targets_in_line_emits_two_paths(): + G = nx.path_graph(4) + paths = nx.all_simple_edge_paths(G, 0, [2, 3]) + assert {tuple(p) for p in paths} == {((0, 1), (1, 2)), ((0, 1), (1, 2), (2, 3))} + + +def test_all_simple_edge_paths_ignores_cycle(): + G = nx.cycle_graph(3, create_using=nx.DiGraph()) + G.add_edge(1, 3) + paths = nx.all_simple_edge_paths(G, 0, 3) + assert {tuple(p) for p in paths} == {((0, 1), (1, 3))} + + +def test_all_simple_edge_paths_with_two_targets_inside_cycle_emits_two_paths(): + G = nx.cycle_graph(3, create_using=nx.DiGraph()) + G.add_edge(1, 3) + paths = nx.all_simple_edge_paths(G, 0, [2, 3]) + assert {tuple(p) for p in paths} == {((0, 1), (1, 2)), ((0, 1), (1, 3))} + + +def test_all_simple_edge_paths_source_target(): + G = nx.path_graph(4) + paths = nx.all_simple_edge_paths(G, 1, 1) + assert list(paths) == [] + + +def test_all_simple_edge_paths_cutoff(): + G = nx.complete_graph(4) + paths = nx.all_simple_edge_paths(G, 0, 1, cutoff=1) + assert {tuple(p) for p in paths} == {((0, 1),)} + paths = nx.all_simple_edge_paths(G, 0, 1, cutoff=2) + assert {tuple(p) for p in paths} == {((0, 1),), ((0, 2), (2, 1)), ((0, 3), (3, 1))} + + +def test_all_simple_edge_paths_on_non_trivial_graph(): + """ you may need to draw this graph to make sure it is reasonable """ + G = nx.path_graph(5, create_using=nx.DiGraph()) + G.add_edges_from([(0, 5), (1, 5), (1, 3), (5, 4), (4, 2), (4, 3)]) + paths = nx.all_simple_edge_paths(G, 1, [2, 3]) + assert {tuple(p) for p in paths} == { + ((1, 2),), + ((1, 3), (3, 4), (4, 2)), + ((1, 5), (5, 4), (4, 2)), + ((1, 3),), + ((1, 2), (2, 3)), + ((1, 5), (5, 4), (4, 3)), + ((1, 5), (5, 4), (4, 2), (2, 3)), + } + paths = nx.all_simple_edge_paths(G, 1, [2, 3], cutoff=3) + assert {tuple(p) for p in paths} == { + ((1, 2),), + ((1, 3), (3, 4), (4, 2)), + ((1, 5), (5, 4), (4, 2)), + ((1, 3),), + ((1, 2), (2, 3)), + ((1, 5), (5, 4), (4, 3)), + } + paths = nx.all_simple_edge_paths(G, 1, [2, 3], cutoff=2) + assert {tuple(p) for p in paths} == {((1, 2),), ((1, 3),), ((1, 2), (2, 3))} + + +def test_all_simple_edge_paths_multigraph(): + G = nx.MultiGraph([(1, 2), (1, 2)]) + paths = nx.all_simple_edge_paths(G, 1, 1) + assert list(paths) == [] + nx.add_path(G, [3, 1, 10, 2]) + paths = list(nx.all_simple_edge_paths(G, 1, 2)) + assert len(paths) == 3 + assert {tuple(p) for p in paths} == { + ((1, 2, 0),), + ((1, 2, 1),), + ((1, 10, 0), (10, 2, 0)), + } + + +def test_all_simple_edge_paths_multigraph_with_cutoff(): + G = nx.MultiGraph([(1, 2), (1, 2), (1, 10), (10, 2)]) + paths = list(nx.all_simple_edge_paths(G, 1, 2, cutoff=1)) + assert len(paths) == 2 + assert {tuple(p) for p in paths} == {((1, 2, 0),), ((1, 2, 1),)} + + +def test_all_simple_edge_paths_directed(): + G = nx.DiGraph() + nx.add_path(G, [1, 2, 3]) + nx.add_path(G, [3, 2, 1]) + paths = nx.all_simple_edge_paths(G, 1, 3) + assert {tuple(p) for p in paths} == {((1, 2), (2, 3))} + + +def test_all_simple_edge_paths_empty(): + G = nx.path_graph(4) + paths = nx.all_simple_edge_paths(G, 0, 3, cutoff=2) + assert list(paths) == [] + + +def test_all_simple_edge_paths_corner_cases(): + assert list(nx.all_simple_edge_paths(nx.empty_graph(2), 0, 0)) == [] + assert list(nx.all_simple_edge_paths(nx.empty_graph(2), 0, 1)) == [] + assert list(nx.all_simple_edge_paths(nx.path_graph(9), 0, 8, 0)) == [] + + +def hamiltonian_edge_path(G, source): + source = arbitrary_element(G) + neighbors = set(G[source]) - {source} + n = len(G) + for target in neighbors: + for path in nx.all_simple_edge_paths(G, source, target): + if len(path) == n - 1: + yield path + + +def test_hamiltonian__edge_path(): + from itertools import permutations + + G = nx.complete_graph(4) + paths = hamiltonian_edge_path(G, 0) + exact = [list(pairwise([0] + list(p))) for p in permutations([1, 2, 3], 3)] + assert sorted(exact) == [p for p in sorted(paths)] + + +def test_edge_cutoff_zero(): + G = nx.complete_graph(4) + paths = nx.all_simple_edge_paths(G, 0, 3, cutoff=0) + assert list(list(p) for p in paths) == [] + paths = nx.all_simple_edge_paths(nx.MultiGraph(G), 0, 3, cutoff=0) + assert list(list(p) for p in paths) == [] + + +def test_edge_source_missing(): + with pytest.raises(nx.NodeNotFound): + G = nx.Graph() + nx.add_path(G, [1, 2, 3]) + list(nx.all_simple_edge_paths(nx.MultiGraph(G), 0, 3)) + + +def test_edge_target_missing(): + with pytest.raises(nx.NodeNotFound): + G = nx.Graph() + nx.add_path(G, [1, 2, 3]) + list(nx.all_simple_edge_paths(nx.MultiGraph(G), 1, 4)) + + +# Tests for shortest_simple_paths +def test_shortest_simple_paths(): + G = cnlti(nx.grid_2d_graph(4, 4), first_label=1, ordering="sorted") + paths = nx.shortest_simple_paths(G, 1, 12) + assert next(paths) == [1, 2, 3, 4, 8, 12] + assert next(paths) == [1, 5, 6, 7, 8, 12] + assert [len(path) for path in nx.shortest_simple_paths(G, 1, 12)] == sorted( + [len(path) for path in nx.all_simple_paths(G, 1, 12)] + ) + + +def test_shortest_simple_paths_directed(): + G = nx.cycle_graph(7, create_using=nx.DiGraph()) + paths = nx.shortest_simple_paths(G, 0, 3) + assert [path for path in paths] == [[0, 1, 2, 3]] + + +def test_shortest_simple_paths_directed_with_weight_fucntion(): + def cost(u, v, x): + return 1 + + G = cnlti(nx.grid_2d_graph(4, 4), first_label=1, ordering="sorted") + paths = nx.shortest_simple_paths(G, 1, 12) + assert next(paths) == [1, 2, 3, 4, 8, 12] + assert next(paths) == [1, 5, 6, 7, 8, 12] + assert [ + len(path) for path in nx.shortest_simple_paths(G, 1, 12, weight=cost) + ] == sorted([len(path) for path in nx.all_simple_paths(G, 1, 12)]) + + +def test_shortest_simple_paths_with_weight_fucntion(): + def cost(u, v, x): + return 1 + + G = nx.cycle_graph(7, create_using=nx.DiGraph()) + paths = nx.shortest_simple_paths(G, 0, 3, weight=cost) + assert [path for path in paths] == [[0, 1, 2, 3]] + + +def test_Greg_Bernstein(): + g1 = nx.Graph() + g1.add_nodes_from(["N0", "N1", "N2", "N3", "N4"]) + g1.add_edge("N4", "N1", weight=10.0, capacity=50, name="L5") + g1.add_edge("N4", "N0", weight=7.0, capacity=40, name="L4") + g1.add_edge("N0", "N1", weight=10.0, capacity=45, name="L1") + g1.add_edge("N3", "N0", weight=10.0, capacity=50, name="L0") + g1.add_edge("N2", "N3", weight=12.0, capacity=30, name="L2") + g1.add_edge("N1", "N2", weight=15.0, capacity=42, name="L3") + solution = [["N1", "N0", "N3"], ["N1", "N2", "N3"], ["N1", "N4", "N0", "N3"]] + result = list(nx.shortest_simple_paths(g1, "N1", "N3", weight="weight")) + assert result == solution + + +def test_weighted_shortest_simple_path(): + def cost_func(path): + return sum(G.adj[u][v]["weight"] for (u, v) in zip(path, path[1:])) + + G = nx.complete_graph(5) + weight = {(u, v): random.randint(1, 100) for (u, v) in G.edges()} + nx.set_edge_attributes(G, weight, "weight") + cost = 0 + for path in nx.shortest_simple_paths(G, 0, 3, weight="weight"): + this_cost = cost_func(path) + assert cost <= this_cost + cost = this_cost + + +def test_directed_weighted_shortest_simple_path(): + def cost_func(path): + return sum(G.adj[u][v]["weight"] for (u, v) in zip(path, path[1:])) + + G = nx.complete_graph(5) + G = G.to_directed() + weight = {(u, v): random.randint(1, 100) for (u, v) in G.edges()} + nx.set_edge_attributes(G, weight, "weight") + cost = 0 + for path in nx.shortest_simple_paths(G, 0, 3, weight="weight"): + this_cost = cost_func(path) + assert cost <= this_cost + cost = this_cost + + +def test_weighted_shortest_simple_path_issue2427(): + G = nx.Graph() + G.add_edge("IN", "OUT", weight=2) + G.add_edge("IN", "A", weight=1) + G.add_edge("IN", "B", weight=2) + G.add_edge("B", "OUT", weight=2) + assert list(nx.shortest_simple_paths(G, "IN", "OUT", weight="weight")) == [ + ["IN", "OUT"], + ["IN", "B", "OUT"], + ] + G = nx.Graph() + G.add_edge("IN", "OUT", weight=10) + G.add_edge("IN", "A", weight=1) + G.add_edge("IN", "B", weight=1) + G.add_edge("B", "OUT", weight=1) + assert list(nx.shortest_simple_paths(G, "IN", "OUT", weight="weight")) == [ + ["IN", "B", "OUT"], + ["IN", "OUT"], + ] + + +def test_directed_weighted_shortest_simple_path_issue2427(): + G = nx.DiGraph() + G.add_edge("IN", "OUT", weight=2) + G.add_edge("IN", "A", weight=1) + G.add_edge("IN", "B", weight=2) + G.add_edge("B", "OUT", weight=2) + assert list(nx.shortest_simple_paths(G, "IN", "OUT", weight="weight")) == [ + ["IN", "OUT"], + ["IN", "B", "OUT"], + ] + G = nx.DiGraph() + G.add_edge("IN", "OUT", weight=10) + G.add_edge("IN", "A", weight=1) + G.add_edge("IN", "B", weight=1) + G.add_edge("B", "OUT", weight=1) + assert list(nx.shortest_simple_paths(G, "IN", "OUT", weight="weight")) == [ + ["IN", "B", "OUT"], + ["IN", "OUT"], + ] + + +def test_weight_name(): + G = nx.cycle_graph(7) + nx.set_edge_attributes(G, 1, "weight") + nx.set_edge_attributes(G, 1, "foo") + G.adj[1][2]["foo"] = 7 + paths = list(nx.shortest_simple_paths(G, 0, 3, weight="foo")) + solution = [[0, 6, 5, 4, 3], [0, 1, 2, 3]] + assert paths == solution + + +def test_ssp_source_missing(): + with pytest.raises(nx.NodeNotFound): + G = nx.Graph() + nx.add_path(G, [1, 2, 3]) + list(nx.shortest_simple_paths(G, 0, 3)) + + +def test_ssp_target_missing(): + with pytest.raises(nx.NodeNotFound): + G = nx.Graph() + nx.add_path(G, [1, 2, 3]) + list(nx.shortest_simple_paths(G, 1, 4)) + + +def test_ssp_multigraph(): + with pytest.raises(nx.NetworkXNotImplemented): + G = nx.MultiGraph() + nx.add_path(G, [1, 2, 3]) + list(nx.shortest_simple_paths(G, 1, 4)) + + +def test_ssp_source_missing2(): + with pytest.raises(nx.NetworkXNoPath): + G = nx.Graph() + nx.add_path(G, [0, 1, 2]) + nx.add_path(G, [3, 4, 5]) + list(nx.shortest_simple_paths(G, 0, 3)) + + +def test_bidirectional_shortest_path_restricted_cycle(): + cycle = nx.cycle_graph(7) + length, path = _bidirectional_shortest_path(cycle, 0, 3) + assert path == [0, 1, 2, 3] + length, path = _bidirectional_shortest_path(cycle, 0, 3, ignore_nodes=[1]) + assert path == [0, 6, 5, 4, 3] + + +def test_bidirectional_shortest_path_restricted_wheel(): + wheel = nx.wheel_graph(6) + length, path = _bidirectional_shortest_path(wheel, 1, 3) + assert path in [[1, 0, 3], [1, 2, 3]] + length, path = _bidirectional_shortest_path(wheel, 1, 3, ignore_nodes=[0]) + assert path == [1, 2, 3] + length, path = _bidirectional_shortest_path(wheel, 1, 3, ignore_nodes=[0, 2]) + assert path == [1, 5, 4, 3] + length, path = _bidirectional_shortest_path( + wheel, 1, 3, ignore_edges=[(1, 0), (5, 0), (2, 3)] + ) + assert path in [[1, 2, 0, 3], [1, 5, 4, 3]] + + +def test_bidirectional_shortest_path_restricted_directed_cycle(): + directed_cycle = nx.cycle_graph(7, create_using=nx.DiGraph()) + length, path = _bidirectional_shortest_path(directed_cycle, 0, 3) + assert path == [0, 1, 2, 3] + pytest.raises( + nx.NetworkXNoPath, + _bidirectional_shortest_path, + directed_cycle, + 0, + 3, + ignore_nodes=[1], + ) + length, path = _bidirectional_shortest_path( + directed_cycle, 0, 3, ignore_edges=[(2, 1)] + ) + assert path == [0, 1, 2, 3] + pytest.raises( + nx.NetworkXNoPath, + _bidirectional_shortest_path, + directed_cycle, + 0, + 3, + ignore_edges=[(1, 2)], + ) + + +def test_bidirectional_shortest_path_ignore(): + G = nx.Graph() + nx.add_path(G, [1, 2]) + nx.add_path(G, [1, 3]) + nx.add_path(G, [1, 4]) + pytest.raises( + nx.NetworkXNoPath, _bidirectional_shortest_path, G, 1, 2, ignore_nodes=[1] + ) + pytest.raises( + nx.NetworkXNoPath, _bidirectional_shortest_path, G, 1, 2, ignore_nodes=[2] + ) + G = nx.Graph() + nx.add_path(G, [1, 3]) + nx.add_path(G, [1, 4]) + nx.add_path(G, [3, 2]) + pytest.raises( + nx.NetworkXNoPath, _bidirectional_shortest_path, G, 1, 2, ignore_nodes=[1, 2] + ) + + +def validate_path(G, s, t, soln_len, path): + assert path[0] == s + assert path[-1] == t + assert soln_len == sum( + G[u][v].get("weight", 1) for u, v in zip(path[:-1], path[1:]) + ) + + +def validate_length_path(G, s, t, soln_len, length, path): + assert soln_len == length + validate_path(G, s, t, length, path) + + +def test_bidirectional_dijksta_restricted(): + XG = nx.DiGraph() + XG.add_weighted_edges_from( + [ + ("s", "u", 10), + ("s", "x", 5), + ("u", "v", 1), + ("u", "x", 2), + ("v", "y", 1), + ("x", "u", 3), + ("x", "v", 5), + ("x", "y", 2), + ("y", "s", 7), + ("y", "v", 6), + ] + ) + + XG3 = nx.Graph() + XG3.add_weighted_edges_from( + [[0, 1, 2], [1, 2, 12], [2, 3, 1], [3, 4, 5], [4, 5, 1], [5, 0, 10]] + ) + validate_length_path(XG, "s", "v", 9, *_bidirectional_dijkstra(XG, "s", "v")) + validate_length_path( + XG, "s", "v", 10, *_bidirectional_dijkstra(XG, "s", "v", ignore_nodes=["u"]) + ) + validate_length_path( + XG, + "s", + "v", + 11, + *_bidirectional_dijkstra(XG, "s", "v", ignore_edges=[("s", "x")]) + ) + pytest.raises( + nx.NetworkXNoPath, + _bidirectional_dijkstra, + XG, + "s", + "v", + ignore_nodes=["u"], + ignore_edges=[("s", "x")], + ) + validate_length_path(XG3, 0, 3, 15, *_bidirectional_dijkstra(XG3, 0, 3)) + validate_length_path( + XG3, 0, 3, 16, *_bidirectional_dijkstra(XG3, 0, 3, ignore_nodes=[1]) + ) + validate_length_path( + XG3, 0, 3, 16, *_bidirectional_dijkstra(XG3, 0, 3, ignore_edges=[(2, 3)]) + ) + pytest.raises( + nx.NetworkXNoPath, + _bidirectional_dijkstra, + XG3, + 0, + 3, + ignore_nodes=[1], + ignore_edges=[(5, 4)], + ) + + +def test_bidirectional_dijkstra_no_path(): + with pytest.raises(nx.NetworkXNoPath): + G = nx.Graph() + nx.add_path(G, [1, 2, 3]) + nx.add_path(G, [4, 5, 6]) + _bidirectional_dijkstra(G, 1, 6) + + +def test_bidirectional_dijkstra_ignore(): + G = nx.Graph() + nx.add_path(G, [1, 2, 10]) + nx.add_path(G, [1, 3, 10]) + pytest.raises(nx.NetworkXNoPath, _bidirectional_dijkstra, G, 1, 2, ignore_nodes=[1]) + pytest.raises(nx.NetworkXNoPath, _bidirectional_dijkstra, G, 1, 2, ignore_nodes=[2]) + pytest.raises( + nx.NetworkXNoPath, _bidirectional_dijkstra, G, 1, 2, ignore_nodes=[1, 2] + )