class MST:
def __init__(self, G):
self.marked = {}
for vid in G.getVertexIds():
self.marked[vid] = False
self.edges = []
self.pq = MinPQ()
self.weight = 0
self.visit(G, 0)
while not self.pq.isEmpty():
edge = self.pq.delMin()
v = edge.either()
w = edge.other(v)
if self.marked[v] and self.marked[w]:
continue
if not self.marked[v]:
self.visit(G, v)
if not self.marked[w]:
self.visit(G, w)
self.edges.append(edge)
self.weight += edge.getWeight()
def visit(self, G, vid):
self.marked[vid] = True
edges = G.getAdjacentEdges(vid)
for edge in edges:
if not self.marked[edge.other(vid)]:
self.pq.insert(edge)
def getEdges(self):
return self.edges
def getWeight(self):
return self.weight
def buildTrie(self, freq):
pq = MinPQ()
for i in range(0, self.R):
if freq[i] > 0:
pq.insert(Node(i, freq[i], None, None))
if pq.size() == 1:
if freq['\0'] == 0:
pq.insert(Node('\0', 0, None, None))
else:
pq.insert(Node('\1', 0, None, None))
while pq.size() > 1:
left = pq.delMin()
right = pq.delMin()
parent = Node('\0', left.freq + right.freq, left, right)
pq.insert(parent)
return pq.delMin()
class LazyPrimMST:
def __init__(self, G):
self.mst = []
self.pq = MinPQ()
self.marked = [False] * G.Vertex()
self.Weight = 0
for v in range(0, G.Vertex()):
if not self.marked[v]:
self.prim(G, v)
#assert(self.check(G))
def prim(self, G, s):
self.scan(G, s)
while not self.pq.isEmpty():
e = self.pq.delMin()
v = e.either()
w = e.other(v)
assert (self.marked[v] or self.marked[w])
if self.marked[v] and self.marked[w]:
continue
self.mst += [e]
self.Weight += e.weight
if not self.marked[v]:
self.scan(G, v)
if not self.marked[w]:
self.scan(G, w)
def scan(self, G, v):
assert (not self.marked[v])
self.marked[v] = True
for e in G.adj[v]:
if not self.marked[e.other(v)]:
self.pq.insert(e)
def edges(self):
return self.mst
def weight(self):
return self.Weight
'''def check(self, G):
