def test_topological_sort(self):
dg = DirectedGraph()
dg.extend_vertexes("A", "B", "C", "D")
dg.add_new_edge("A", "B")
dg.add_new_edge("B", "C")
dg.add_new_edge("C", "D")
assert dg.topological_sort() == [vt("A"), vt("B"), vt("C"), vt("D")]
dg = DirectedGraph("A", "B", "C")
dg.add_new_edge("A", "B")
dg.add_new_edge("B", "C")
dg.add_new_edge("C", "A")
with pytest.raises(RuntimeError, match="存在环"):
dg.topological_sort()
dg = DirectedGraph("A", "B", "C", "D")
dg.add_new_edge("A", "B")
dg.add_new_edge("A", "D")
dg.add_new_edge("B", "C")
dg.add_new_edge("D", "C")
result = dg.topological_sort()
assert result == [
vt("A"), vt("B"), vt("D"), vt("C")
] or result == [vt("A"), vt("D"), vt("B"),
vt("C")]
def test_create(self):
dg = DirectedGraph()
dg.extend_vertexes("A", "B", "C", "D")
dg.add_new_edge("A", "B")
dg.add_new_edge("B", "C")
dg.add_new_edge("C", "D")
assert [v.name for v in dg.vertexes] == ["A", "B", "C", "D"]
assert dg.adjacency_dict == {
vt("A"): [vt("B")],
vt("B"): [vt("C")],
vt("C"): [vt("D")],
vt("D"): [],
}
with pytest.raises(exceptions.VertexNotExistError):
dg.get_vertex_by_name("E")
with pytest.raises(exceptions.VertexNotExistError):
dg.add_new_edge("E", "B")