def KruskalMST(graph:EdgeWeightedGraph):
MST = []
EdgeSequence=[]
UF = UnionFind(graph.numVertices())
#Pre-processing the edges
PQ = []
for item in graph.adj:
PQ += graph.adj[item]
heapq.heapify(PQ)
while (len(PQ)>0) & (len(MST) < graph.numVertices()-1):
e = heapq.heappop(PQ)
v = e.either()
w = e.other(v)
if (UF.connected(v,w)):
continue
else:
UF.union(v,w)
heapq.heappush(MST, e)
EdgeSequence.append(e)
cluster = set()
for item in UF.id:
cluster.add(item)
print ("cluster:", cluster, len(cluster))
print (e.weight)
return MST
def main():
V = set()
file_handle = open("Edges.txt", 'r')
for line in file_handle:
if len(line.split()) <= 2:
numNodes = int(line.split()[0])
numEdges = int(line.split()[1])
graph = EdgeWeightedGraph(numNodes)
else:
v = int(line.split()[0])
w = int(line.split()[1])
weight = int(line.split()[2])
edge = Edge(v, w, weight)
graph.addEdge(edge)
V.add(v)
V.add(w)
# for item in graph.adj[1]:
# print(item.either(),item.other(item.either()), item.weight)
#
# print ("min",minEdge(graph.adj[1]).weight)
# #print(graph.adj[1][1].either(),graph.adj[1][1].other(graph.adj[1][1].either()), graph.adj[1][1].weight)
# #print(graph.adj[1][2].either(),graph.adj[1][2].other(graph.adj[1][2].either()), graph.adj[1][2].weight)
# #print(graph.adj[1][1] > graph.adj[1][2] )
Primedges = primMST(graph, V, 1)
sum = 0
for item in Primedges:
sum += item.weight
print(sum)
def LoadGraph(filename):
file_handle = open(filename, 'r')
for line in file_handle:
if len(line.split()) <= 1:
numNodes = int(line.split()[0])
graph = EdgeWeightedGraph(numNodes)
else:
v = int(line.split()[0])
w = int(line.split()[1])
weight = int(line.split()[2])
edge = Edge(v, w, weight)
graph.addEdge(edge)
return graph
def LoadGraph(filename):
file_handle = open(filename, 'r')
for line in file_handle:
if len(line.split()) <= 1:
numNodes = int(line.split()[0])
graph = EdgeWeightedGraph(numNodes)
else:
v = int(line.split()[0])
w = int(line.split()[1])
weight = int(line.split()[2])
edge = Edge(v, w, weight)
graph.addEdge(edge)
return graph
def main():
G = EdgeWeightedGraph(16384,0)
mst = PrimMST(G)
mst.toString()
mst.sum_weight
class Network:
graph = EdgeWeightedGraph()
path = []
def __init__(self):
graph = EdgeWeightedGraph()
def readGraph(self, filename):
f = open(filename, 'r')
for line in f:
v1, v2, v3 = line.split(" ")
weight = float(v3)
self.graph.addEdge(v1, v2, weight, 0, 0)
def createPath(self):
e1 = Edge("A", "B", 0.0, 0, 0)
e2 = Edge("B", "C", 0.0, 0, 0)
self.path.append(e1)
self.path.append(e2)
# draw the graph
def drawGraph(self, filename):
# create an empty undirected graph
G = pgv.AGraph('graph myGraph {}')
# draw edges
for n in self.graph.V():
for e in self.graph.adj(n):
x = e.either()
y = e.other(x)
G.add_edge(x, y, e.weight, label=e.weight)
#highlight edges in path with red color
for e in self.path:
v1 = e.either()
v2 = e.other(v1)
edge = G.get_edge(v1, v2)
edge.attr['color'] = 'red'
# render graph into PNG file
G.draw(filename, prog='dot')
os.startfile(filename)
class Question4b:
graph = EdgeWeightedGraph()
storeEdges = []
def __init__(self):
graph = EdgeWeightedGraph()
def readGraph(self, filename, nodeName, nodeWeight):
f = open(filename, 'r')
for line in f:
v1, v2, v3 = line.split(" ")
weight = float(v3)
travelTime = 0
costs = 0
self.graph.addEdge(v1, v2, weight, travelTime, costs)
self.getVerticesFromEither(nodeName)
self.displayVerticesAndDistance(nodeWeight, nodeName)
def getVerticesFromEither(self, nodeName):
for e in self.graph.adj(nodeName):
x = e.either()
y = e.other(x)
if x is nodeName:
self.storeEdges.append(e)
elif y is nodeName:
self.storeEdges.append(e)
def displayVerticesAndDistance(self, edgeWeight, nodeName):
for x in range(0, len(self.storeEdges)):
if self.storeEdges[x].weight < edgeWeight:
if nodeName is self.storeEdges[x].v:
print "node: " + str(self.storeEdges[x].w),
print " weight: " + str(self.storeEdges[x].weight)
if nodeName is self.storeEdges[x].w:
print "node: " + str(self.storeEdges[x].v),
print " weight: " + str(self.storeEdges[x].weight)
def drawGraph(self, filename):
Gpgv = pgv.AGraph('graph myGraph {}')
for n in G.V():
for e in G.adj(n):
x = e.either()
y = e.other(x)
Gpgv.add_edge(x, y, e.weight, label=e.weight)
for e in self.path:
v1 = e.either()
v2 = e.other(v1)
edge = Gpgv.get_edge(v1, v2)
edge.attr['color'] = 'red'
Gpgv.draw(filename, prog='dot')
os.startfile(filename)
G = EdgeWeightedGraph()
G.readGraph("tinyEWG.txt")
s = G.V()[5]
sp = DijkstraSP(G, s, "distance")
for v in G.V():
print str(s) + " to " + str(v) + " (" + str(sp.distTo[v]) + "):",
for e in reversed(sp.pathTo(6)):
sp.createPath(e.src(), e.dest(), e.weight, 0, 0)
print str(e.src()) + "->" + str(e.dest()) + " " + str(e.weight) + " ",
print
filename = "dijkstragenerate.png"
sp.drawGraph(filename)
if not self.marked[v] == True:
self._visit(ewg, v)
if not self.marked[w] == True:
self._visit(ewg, w)
def _visit(self, ewg, v):
self.marked[v] = True
for e in ewg.adj(v):
if not self.marked[e.other(v)] == True:
self.pq.enqueue(e)
def edges(self):
return self.mst
j = EdgeWeightedGraph(6)
e1 = Edge(5, 1, 10)
j.addEdge(e1)
e2 = Edge(1, 2, 4)
j.addEdge(e2)
e3 = Edge(1, 3, 3)
j.addEdge(e3)
e4 = Edge(3, 4, 4)
j.addEdge(e4)
e5 = Edge(2, 0, 5)
j.addEdge(e5)
e6 = Edge(0, 4, 4)
j.addEdge(e6)
w = LazyPrimMST(j)
for x in w.edges():
y = e.other(x)
Gpgv.add_edge(x, y, e.weight, label=e.weight)
for e in self.path:
v1 = e.either()
v2 = e.other(v1)
edge = Gpgv.get_edge(v1, v2)
edge.attr['color'] = 'red'
Gpgv.draw(filename, prog='dot')
os.startfile(filename)
''' end question 3a '''
G = EdgeWeightedGraph()
G.readGraph("tinyEWG.txt")
mst = PrimMST(G, "distance")
sum = 0
for e in mst.edges():
eV = e.either() #get left node
eW = e.other(eV) #get right node
mst.createPath(eV, eW, e.weight, 0, 0)
print e.toString()
sum += e.weight
filename = "primgenerate.png"
mst.drawGraph(filename)
print sum
def __init__(self):
graph = EdgeWeightedGraph()
if self.pq.contains(w):
self.pq.decreaseKey(w, self.distTo[w])
else:
self.pq.insert(w, self.distTo[w])
def edges(self):
mst = []
for v in range(0, len(self.edgeTo)):
e = self.edgeTo[v]
if e != None:
mst += [e]
return mst
def weight(self):
weight = 0.0
for e in self.edges():
weight += e.Weight()
return weight
def check(self, G):
pass
if __name__ == '__main__':
myin = In(sys.argv[1], None)
G = EdgeWeightedGraph(myin)
mst = PrimMST(G)
for e in mst.edges():
print(e)
print("%.5f\n" % mst.weight())
# Mark a vertex when visit it and add all the adjacent edges to it on to the MinPQ
def _visit(self, vertex, graph):
self._marked[vertex] = True
for edge in graph.adj(vertex):
if not self._marked[edge.other(vertex)]:
self._pq.insert(edge)
# All the edges in the minimum spanning tree
def edges(self):
return self._mst
# The total weight of the minimum spanning tree
def weight(self):
weight = 0
for edge in self._mst:
weight += edge.weight()
return weight
# Unit Test
if __name__ == "__main__":
file_name = argv[1]
graph = EdgeWeightedGraph.read_file(file_name)
mst = MSTPrim(graph)
for edge in mst.edges():
print(edge)
print(mst.weight())
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
if __name__ == '__main__':
inputFile = sys.argv[1]
g = EdgeWeightedGraph(inputFile)
mst = MST(g)
for e in mst.getEdges():
print e
print mst.getWeight()
if __name__ == "__main__":
import sys
from PrimMST import PrimMST
from EdgeWeightedGraph import EdgeWeightedGraph
flag = int(sys.argv[1])
numpoints = int(sys.argv[2])
numtrials = int(sys.argv[3])
dimension = int(sys.argv[4])
ave_weight = []
# simulate trials
for i in range(numtrials):
# generate random complete undirected graph
G = EdgeWeightedGraph(numpoints, dimension)
mst = PrimMST(G)
# debug
if flag == 1:
mst.toString()
ave_weight.append(mst.sum_weight)
print("%f %d %s %s" %
(sum(ave_weight) / numtrials, numpoints, numtrials, dimension))
self._visit(ewg,v) if not self.marked[w] == True : self._visit(ewg,w) def _visit(self,ewg,v): self.marked[v] = True for e in ewg.adj(v): if not self.marked[e.other(v)] == True : self.pq.enqueue(e) def edges(self): return self.mst j = EdgeWeightedGraph(6) e1 = Edge(5,1,10) j.addEdge(e1) e2 = Edge(1,2,4) j.addEdge(e2) e3 = Edge(1,3,3) j.addEdge(e3) e4 = Edge(3,4,4) j.addEdge(e4) e5 = Edge(2,0,5) j.addEdge(e5) e6 = Edge(0,4,4) j.addEdge(e6) w = LazyPrimMST(j) for x in w.edges():