class LazyPrimMST:
def __init__(self, g):
self.pq = MinPQ()
self.marked = []
self.mst = Queue()
for i in range(g.v):
self.marked.append(False)
self.visit(g, 0)
while not self.pq.is_empty():
e = self.pq.del_min()
v = e.either()
w = e.other(v)
if self.marked[v] and self.marked[w]:
continue
self.mst.enqueue(e)
if not self.marked[v]:
self.visit(g, v)
if not self.marked[w]:
self.visit(g, w)
def visit(self, g, v):
self.marked[v] = True
for e in g.adj[v]:
if not self.marked[e.other(v)]:
self.pq.insert(e)
class KruskalMST:
def __init__(self, g):
self.mst = Queue()
self.pq = MinPQ()
self.uf = UF(g.v)
for e in g.edges:
self.pq.insert(e)
while not self.pq.is_empty() and self.mst.size() < g.v - 1:
e = self.pq.del_min()
v = e.either()
w = e.other(v)
if self.uf.connected(v, w):
continue
self.mst.enqueue(e)
self.uf.union(v, w)
