def test_directed_graph():
g = DirectedGraph()
assert num_vertices(g) == 0
u = add_vertex(g)
assert num_vertices(g) == 1
v = add_vertex(g)
assert num_vertices(g) == 2
w = add_vertex(g)
assert num_vertices(g) == 3
assert num_edges(g) == 0
e_uv, _ = add_edge(u, v, g)
assert num_edges(g) == 1
e_uv1, _ = add_edge(u, v, g)
assert num_edges(g) == 2
e_uw, _ = add_edge(u, w, g)
assert num_edges(g) == 3
e_vw, _ = add_edge(v, w, g)
assert num_edges(g) == 4
print("Edges = %s" % {e for e in edges(g)})
print("Out-edges(%s) = %s" % (u, {e for e in out_edges(u, g)}))
assert out_degree(u, g) == 3
assert out_degree(v, g) == 1
assert out_degree(w, g) == 0
print("Removing %s" % e_uv)
remove_edge(e_uv, g)
assert num_edges(g) == 3
print("Removing %s" % e_uv1)
remove_edge(e_uv1, g)
assert num_edges(g) == 2
print("Removing %s" % v)
remove_vertex(v, g)
assert num_vertices(g) == 2
print("Edges = %s" % {e for e in edges(g)})
assert num_edges(g) == 1
print("Out-edges(%s) = %s" % (u, {e for e in out_edges(u, g)}))
assert out_degree(u, g) == 1
assert out_degree(w, g) == 0
print(g.to_dot())
def test_cut_diamond():
g = DirectedGraph(4)
(e01, _) = add_edge(0, 1, g)
(e02, _) = add_edge(0, 2, g)
(e13, _) = add_edge(1, 3, g)
(e23, _) = add_edge(2, 3, g)
obtained = cut(0, g, lambda e, g: e in {e01, e02})
assert obtained == {1, 2}
obtained = cut(0, g, lambda e, g: e in {e13, e23})
assert obtained == {3}
def make_graph(edges_set: set) -> DirectedGraph:
g = DirectedGraph()
n = 0
for (u, v) in edges_set:
assert u >= 0
while n <= u:
add_vertex(g)
n += 1
while n <= v:
add_vertex(g)
n += 1
add_edge(u, v, g)
return g
def test_cut():
g = DirectedGraph(3)
(e01, _) = add_edge(0, 1, g)
(e12, _) = add_edge(1, 2, g)
obtained = cut(0, g, lambda e, g: e in {e01})
assert obtained == {1}
obtained = cut(0, g, lambda e, g: e in {e12})
assert obtained == {2}
obtained = cut(0, g, lambda e, g: False)
assert obtained == {2}
obtained = cut(0, g, lambda e, g: True)
assert obtained == {1}
def test_topological_sort():
g = DirectedGraph(6)
for (u, v) in [(0, 1), (2, 4), (2, 5), (0, 3), (1, 4), (4, 3)]:
add_edge(u, v, g)
l = topological_sort(g)
assert list(l) == [2, 5, 0, 1, 4, 3]
def make_binary_tree(n=10):
g = DirectedGraph(n)
for u in range(n - 1):
add_edge(int(u / 2), u + 1, g)
return g
