def test_Find_OnNotConnectedNodes_ReturnsFalse(self):
uf = UnionFind(5)
uf.union(1, 2)
uf.union(2, 3)
uf.union(3, 4)
self.assertEqual(uf.find(1), uf.find(3))
self.assertEqual(uf.find(2), uf.find(4))
self.assertNotEqual(uf.find(1), uf.find(5))
self.assertNotEqual(uf.find(4), uf.find(5))
def find_clusters(self, count):
sorted_edges = sorted(self._edges, key=attrgetter("cost"))
uf = UnionFind(self._num_vertices)
for index, edge in enumerate(sorted_edges):
if count != uf.count and not uf.connected(edge.from_vertex,
edge.to_vertex):
uf.union(edge.from_vertex, edge.to_vertex)
if uf.count == count and not uf.connected(edge.from_vertex,
edge.to_vertex):
return edge.cost
def test_GetCount_OnNonEffectUnions_RemainsTheSame(self):
uf = UnionFind(10)
uf.union(1, 2)
self.assertEqual(uf.count, 9)
uf.union(1, 2)
self.assertEqual(uf.count, 9)
uf.union(2, 3)
self.assertEqual(uf.count, 8)
uf.union(1, 3)
self.assertEqual(uf.count, 8)
def test_Union_ThreeNodesInTwoPairs_AllHaveTheSameParent(self):
uf = UnionFind(3)
uf.union(1, 2)
uf.union(2, 3)
self.assertEqual(uf.find(1), uf.find(3))
def test_Union_TwoNodes_HaveTheSameParent(self):
uf = UnionFind(2)
uf.union(1, 2)
self.assertEqual(uf.find(1), uf.find(2))