def test_cycle(self):
""" Tests if the union-find algorithm for finding cycles is working
:return:
"""
g = Graph(3)
g.add_edge(0, 1)
g.add_edge(0, 2)
# g.add_edge(0, 0)
assert g.contains_cycle() is False
g.add_edge(1, 2)
assert g.contains_cycle() is True
def graph_for_transversal():
g = Graph()
g.add_edge(0, 1)
g.add_edge(0, 2)
g.add_edge(4, 4)
g.add_edge(2, 4)
g.add_edge(1, 2)
g.add_edge(2, 0)
g.add_edge(2, 3)
g.add_edge(3, 3)
g.add_edge(5, 5)
g.add_edge(1, 5)
return g
def test_kruskal_mst(self):
g = Graph(4)
g.add_edge(0, 1, 10)
g.add_edge(0, 2, 6)
g.add_edge(0, 3, 5)
g.add_edge(1, 3, 15)
g.add_edge(2, 3, 4)
expected = [
Edge(source=2, destination=3, weight=4),
Edge(source=0, destination=3, weight=5),
Edge(source=0, destination=1, weight=10)
]
assert g.kruskal_mst() == expected
def test_prim_mst_with_heap(self):
expected = set()
expected.update([
Edge(source=0, destination=1, weight=2),
Edge(source=1, destination=2, weight=3),
Edge(source=0, destination=3, weight=6),
Edge(source=1, destination=4, weight=5),
])
g = Graph(5)
g.add_edge(0, 1, 2)
g.add_edge(0, 3, 6)
g.add_edge(1, 2, 3)
g.add_edge(1, 3, 8)
g.add_edge(2, 4, 7)
g.add_edge(3, 4, 9)
g.add_edge(1, 4, 5)
assert g.prim_mst_with_heap() == expected
def test_prim_mst(self):
expected = set()
expected.update([
Edge(source=0, destination=1, weight=2),
Edge(source=1, destination=2, weight=3),
Edge(source=0, destination=3, weight=6),
Edge(source=1, destination=4, weight=5),
])
g = Graph(5)
g.add_edge(0, 1, 2)
g.add_edge(0, 3, 6)
g.add_edge(1, 2, 3)
g.add_edge(1, 3, 8)
g.add_edge(2, 4, 7)
g.add_edge(3, 4, 9)
g.add_edge(1, 4, 5)
# This symmetry is needed for adjacency matrix version
g.add_edge(1, 0, 2)
g.add_edge(3, 0, 6)
g.add_edge(2, 1, 3)
g.add_edge(3, 1, 8)
g.add_edge(4, 2, 7)
g.add_edge(4, 3, 9)
g.add_edge(4, 1, 5)
assert g.prim_mst() == expected