def test_vertices():
g = Graph()
for i in range(10):
assert len(g.vertices()) == g.get_vertex_count()
g.add_vertex(i)
assert i in g.vertices()
for i in range(10):
g.remove_vertex(i)
assert len(g.vertices()) == g.get_vertex_count()
assert i not in g.vertices()
def test_neighbours():
g = Graph()
for i in range(10):
g.add_vertex(i)
for v in g.vertices():
for w in range(v):
assert len(g.neighbours(v)) == g.degree(v)
assert len(g.neighbours(v, outgoing = False)) == g.degree(v, outgoing = False)
assert len(g.neighbours(v, ingoing = False)) == g.degree(v, ingoing = False)
assert g.degree(v) == g.degree(v, outgoing = False) + g.degree(v, ingoing = False)
g.add_edge(v,w,v-w)
assert (w,v-w) in g.neighbours(v)
assert (v,v-w) in g.neighbours(w)
assert (w,v-w) in g.neighbours(v, ingoing = False)
assert (v,v-w) in g.neighbours(w, outgoing = False)
assert (w,v-w) not in g.neighbours(v, outgoing = False)
assert (v,v-w) not in g.neighbours(w, ingoing = False)