def test_breadth_first_traverse_different_origins():
g = Graph()
a = g.add_vertex('A')
b = g.add_vertex('B')
c = g.add_vertex('C')
d = g.add_vertex('D')
e = g.add_vertex('E')
f = g.add_vertex('F')
g.add_edge(a, b)
g.add_edge(b, c)
g.add_edge(b, d)
g.add_edge(c, e)
g.add_edge(d, f)
g.add_edge(e, f)
assert g.breadth_first_traverse(a) == ['A', 'B', 'C', 'D', 'E', 'F']
assert g.breadth_first_traverse(f) == ['F', 'D', 'E', 'B', 'C', 'A']
assert g.breadth_first_traverse(c) == ['C', 'B', 'E', 'A', 'D', 'F']
def test_breadth_first_traverse_with_islands():
g = Graph()
pan = g.add_vertex('Pandora')
are = g.add_vertex('Arendelle')
met = g.add_vertex('Metroville')
mon = g.add_vertex('Monstropolis')
nab = g.add_vertex('Naboo')
nar = g.add_vertex('Narnia')
g.add_edge(pan, are)
g.add_edge(are, met)
g.add_edge(are, mon)
g.add_edge(met, mon)
g.add_edge(nar, nab)
places = g.breadth_first_traverse(pan)
assert places == ['Pandora', 'Arendelle', 'Metroville', 'Monstropolis']
