def spanning_tree(g: Graph) -> {(str, str, int)}:
answer = set()
edges = sorted((e[2], e[0], e[1]) for e in g if len(e) != 1)
components = EquivalenceClass(g.all_nodes())
n = len(g.all_nodes())
for v, o, d in edges:
if n == 1:
return answer
if not components.in_same_class(o, d):
answer.add((o, d, v))
components.merge_classes_containing(o, d)
n -= 1
return answer
def spanning_tree(g : Graph) -> {(str,str,int)}:
answer = set()
edges = sorted( (e[2],e[0],e[1]) for e in g if len(e) != 1)
components = EquivalenceClass(g.all_nodes())
n = len(g.all_nodes())
for v,o,d in edges:
if n == 1:
return answer
if not components.in_same_class(o, d):
answer.add((o,d,v))
components.merge_classes_containing(o, d)
n -= 1
return answer
def minimum_spanning_tree(g):
from priorityqueue import PriorityQueue as PQ
from equivalence import EquivalenceClass as EC
answer = Graph()
ec = EC(g.nodes())
# Smaller edge values have higher priority
for e in PQ(g.edges(),key=(lambda e : g.edge_value(e)),reverse=True):
if not ec.in_same_class(e[0],e[1]):
ec.merge_classes_containing(e[0],e[1])
answer.add_edge(e,g.edge_value(e))
if answer.edge_count() == g.node_count()-1:
break
else: return None
return answer
def minimum_spanning_tree(g):
from priorityqueue import PriorityQueue as PQ
from equivalence import EquivalenceClass as EC
answer = Graph()
ec = EC(g.nodes())
# Smaller edge values have higher priority
for e in PQ(g.edges(), key=(lambda e: g.edge_value(e)), reverse=True):
if not ec.in_same_class(e[0], e[1]):
ec.merge_classes_containing(e[0], e[1])
answer.add_edge(e, g.edge_value(e))
if answer.edge_count() == g.node_count() - 1:
break
else:
return None
return answer
def connected_components(g):
from equivalence import EquivalenceClass as EC
ec = EC(g.nodes())
for e in g.edges():
ec.merge_classes_containing(e[0], e[1])
return ec.all_classes()
def connected_components(g):
from equivalence import EquivalenceClass as EC
ec = EC(g.nodes())
for e in g.edges():
ec.merge_classes_containing(e[0],e[1])
return ec.all_classes()
def setup(size):
global ec
ec = EquivalenceClass([i for i in range(size)])