def test_components(self):
g = SimpleGraph()
g.from_graph_sequence([4, 3, 3, 2, 2, 1, 1])
comps = g.components()
assert comps[1] == comps[2] == comps[3] == comps[4] == comps[5]
assert comps[6] == comps[7]
assert comps[1] != comps[6]
def get_minimum_spanning_tree_kruskal(g: SimpleGraph) -> SimpleGraph:
"""
Przyjmuje graf
Zwraca jego minimalne drzewo rozpinające
Korzysta z algorytmu kruskala
"""
# minimum spanning tree
mst = SimpleGraph(len(g))
Q = []
for edge in g.edges:
Q.append(edge)
while Q and not mst.is_connected_graph():
Q.sort(key=lambda e: e.weight)
current_edge = Q.pop(0)
comps = mst.components()
if comps[current_edge.begin] != comps[current_edge.end]:
mst.edges.add(current_edge)
return mst