def __call__(self, chromosome, **kwargs):
'''
Parameters:
chromosome : is a EdgeSet type or a Bag
Results :
_cost : Number
the edgeset cost
nro_components : int
graph components identified
'''
assert isinstance(
chromosome, EdgeSet
), f"unsupported operation for chromosome type {type(chromosome)}"
disjointset = DisjointSets()
_cost = 0
GRAPH = self.STPG.graph
for v, u in chromosome:
if not GRAPH.has_edge(v, u):
raise RuntimeError("STPG instance has not this edge")
_cost += GRAPH.weight(v, u)
if v not in disjointset:
disjointset.make_set(v)
if u not in disjointset:
disjointset.make_set(u)
disjointset.union(v, u)
nro_components = len(disjointset.get_disjoint_sets())
_cost += self.penality_function(nro_components)
return _cost, nro_components
def __call__(self, parent_a, parent_b):
assert isinstance(
parent_a, EdgeSet
), f'parent_a has to be EdgeSet type. Give was {type(parent_a)}'
assert isinstance(
parent_b, EdgeSet
), f'parent_b has to be EdgeSet type. Give was {type(parent_b)}'
edges = parent_a | parent_b
done = DisjointSets()
for v in edges.vertices:
done.make_set(v)
edges = set(edges)
result = EdgeSet()
while edges and len(done.get_disjoint_sets()) > 1:
edge = sample(edges, k=1)[0]
y, z = edge[0], edge[1]
if done.find(y) != done.find(z):
result.add(edge)
done.union(y, z)
edges.discard(edge)
return result
def test_EvaluateZeroChromossome(self):
stpg = self.stpg
graph = self.stpg.graph
nro_terminals = stpg.nro_terminals
terminals = stpg.terminals
disset = DisjointSets()
for v in terminals:
disset.make_set(v)
edges_sum = 0
done = set()
for t in terminals:
done.add(t)
for v in graph.adjacent_to(t):
if v in terminals and v not in done:
disset.union(t, v)
edges_sum += graph.weight(t, v)
qtd_disjoint_sets = len(disset.get_disjoint_sets())
expected_lenght = stpg.nro_nodes - stpg.nro_terminals
chromosome = '0' * expected_lenght
evaluator = EvaluateKruskalBased(stpg)
evaluator_cost, qtd_partitions = evaluator(chromosome)
self.assertEqual(evaluator_cost,
((qtd_partitions - 1) * 1_000) + edges_sum)
self.assertEqual(evaluator_cost,
((qtd_disjoint_sets - 1) * 1_000) + edges_sum)
self.assertEqual(qtd_partitions, qtd_disjoint_sets)
def __call__(self, red, blue):
assert isinstance(
red, UGraph), f'red parent must be UGraph. Given {type(red)}'
assert isinstance(
blue, UGraph), f'blue parent must be UGraph. Given {type(blue)}'
done = DisjointSets()
union_g = UGraph()
for v, u in red.gen_undirect_edges():
union_g.add_edge(v, u)
for v, u in blue.gen_undirect_edges():
union_g.add_edge(v, u)
for v in union_g.vertices:
done.make_set(v)
all_edges = set()
for edge in union_g.gen_undirect_edges():
all_edges.add(edge)
result = UGraph()
while all_edges and len(done.get_disjoint_sets()) > 1:
edge = sample(all_edges, k=1)[0]
v, u = edge[0], edge[1]
if done.find(v) != done.find(u):
result.add_edge(v, u)
done.union(v, u)
all_edges.remove(edge)
return result
def __call__(self, chromosome, **kwargs):
GRAPH = self.STPG.graph
penality = self.penality_function
vertices = self.vertices_from_chromosome(chromosome)
# instânciando variáveis e funções auxiliares
queue = PriorityQueue()
dones = set()
# adiciona uma aresta se os vértices extremos da aresta
# estão contidos no conjunto vertices
# mantém essas arestas em uma fila de prioridades para
# formar uma MST baseado no algoritmo de Kruskal
# (o trabalho de Kapsalis utilizava o algoritmo de Prim)
for v in vertices:
dones.add(v)
for u in GRAPH.adjacent_to(v):
if (u in vertices) and (u not in dones):
weight = GRAPH.weight(v, u)
queue.push(weight, (v, u, weight))
## Monta a MST baseado no algoritmo de Kruskal
DS = DisjointSets()
for v in vertices:
DS.make_set(v)
total_cost = 0
while queue:
v, u, weight = queue.pop()
if DS.find(v) != DS.find(u):
total_cost += weight
DS.union(v, u)
# Repare que não construimos a MST mas apenas
# definimos os conjuntos disjuntos.
# a quantidade de partições se refere a
# quantidade de parents distintos temos no conjunto disjunto.
qtd_partition = len(DS.get_disjoint_sets())
total_cost += penality(qtd_partition)
return total_cost, qtd_partition
def test_inserting_item(self):
DS = DisjointSets()
for item in range(3, 50, 10):
DS.make_set(item)
self.assertEqual(len(DS), 5)
self.assertEqual(len(DS), len(DS.get_disjoint_sets()))
with self.assertRaises(ValueError):
DS.make_set(13)
## check ignore_previous
self.assertTrue(33 in DS)
DS.make_set(33, ignore_previous=True)
self.assertTrue(not 171 in DS)
self.assertFalse(171 in DS)
def __call__(self):
result = UGraph()
done = DisjointSets()
edges = [(u, v) for u, v in self.stpg.graph.gen_undirect_edges()]
shuffle(edges)
for v in self.stpg.terminals:
done.make_set(v)
while edges and len(done.get_disjoint_sets()) > 1:
edge = edges.pop()
y, z = edge[0], edge[1]
if y not in done: done.make_set(y)
if z not in done: done.make_set(z)
if done.find(y) != done.find(z):
result.add(y, z)
done.union(y, z)
return result
def __call__(self, treegraph: UGraph):
GRAPH = self.stpg.graph
disjointset = DisjointSets()
result = UGraph()
for v in treegraph.vertices:
disjointset.make_set(v)
# remove edge
edges = [edge for edge in treegraph.gen_undirect_edges()]
index = randint(0, len(edges))
for i, edge in enumerate(edges):
if index != i:
result.add_edge(*edge)
disjointset.union(*edge)
candidates = list()
components = disjointset.get_disjoint_sets()
lesser_idx = min(components, key=lambda key: len(components[key]))
keys = components.keys() - set([lesser_idx])
# replace edge
lesser_component = components[lesser_idx]
for key in keys:
other_component = components[key]
for v in lesser_component:
for w in GRAPH.adjacent_to(v):
if w in other_component:
candidates.append((v, w))
shuffle(candidates)
while candidates:
v, w = candidates.pop()
if disjointset.find(v) != disjointset.find(w):
result.add_edge(v, w)
disjointset.union(v, w)
break
return result
def __call__(self, tree):
GRAPH = self.STPG.graph
total_cost = 0
qtd_partition = 0
DS = DisjointSets()
for v in tree.vertices:
DS.make_set(v)
for v, u in tree.gen_undirect_edges():
if DS.find(v) == DS.find(u):
## trocar isso por um log
print("FOI IDENTIFICADO UM CICLO EM UMA DAS SOLUÇÕES")
DS.union(v, u)
total_cost += GRAPH.weight(v, u)
qtd_partition = len(DS.get_disjoint_sets())
if self.apply_penalization:
total_cost += self.penality(qtd_partition)
return total_cost, qtd_partition
def gen_random_kruskal(stpg: SteinerTreeProblem):
terminals = set(stpg.terminals)
edges = [(u, v) for u, v in stpg.graph.gen_undirect_edges()]
shuffle(edges)
done = DisjointSets()
for v in terminals:
done.make_set(v)
result = EdgeSet()
while edges and len(done.get_disjoint_sets()) > 1:
edge = edges.pop()
y, z = edge[0], edge[1]
if y not in done: done.make_set(y)
if z not in done: done.make_set(z)
if done.find(y) != done.find(z):
result.add(y, z)
done.union(y, z)
terminals.discard(y)
terminals.discard(z)
return result