def Dijkstra_p(G,start,end=None):
D = {} # dictionary of final distances
P = {} # dictionary of predecessors
Q = priorityDictionary() # est.dist. of non-final vert.
Q[start] = 0
comm = PSim(len(Q)+1)
if comm.rank==0:
i = 1
for v in Q:
D[v] = Q[v]
if v == end: break
comm.send(i, v)
i = i + 1
else:
v = comm.recv(0)
for w in G[v]:
vwLength = D[v] + G[v][w]
if w in D:
if vwLength < D[w]:
raise ValueError, "Dijkstra: found better path to already-final vertex"
elif w not in Q or vwLength < Q[w]:
Q[w] = vwLength
P[w] = v
return (D,P)
def Dijkstra(self):
distances = {}
individual_dist = {}
reverse = {}
path = {}
final_dist = {} # dictionary of final distances
Q = priorityDictionary() # distances of non final predecessors
Q[self.start] = 0
visited = []
for road in Q:
if road in distances:
individual_dist[road] = distances[road]
if road in visited:
continue
if road not in visited:
visited.append(road)
final_dist[road] = Q[road]
if road in reverse:
if reverse[road] == 0.3:
if self.direction == '+':
self.direction == '-'
else:
self.direction == '+'
for neighbour in self.intersctn[road]:
if road == self.end:
starting = self.intersctn[neighbour][road]
ending = self.endPoint
else:
starting = self.intersctn[road][neighbour]
ending = self.intersctn[neighbour][road]
if neighbour in visited or starting == ending:
continue
dist, reverseTime = self.calcDist(road, starting, neighbour,
ending, self.direction)
totalDist = final_dist[road] + dist
if neighbour not in Q or (totalDist <= Q[neighbour]):
Q[neighbour] = totalDist
path[neighbour] = road
reverse[neighbour] = reverseTime
distances[neighbour] = dist + reverseTime
if road == self.start:
distances[self.start], reverse[
self.start] = self.calcDist(
self.start, self.startPoint, neighbour,
self.intersctn[self.start][neighbour],
self.direction)
if len(visited) == self.noOfRoads:
break
return (distances, path, reverse)
def Dijkstra(self):
distances={}
individual_dist={}
reverse={}
path={}
final_dist = {} # dictionary of final distances
Q = priorityDictionary() # distances of non final predecessors
Q[self.start] = 0
visited=[]
for road in Q:
if road in distances:
individual_dist[road]=distances[road]
if road in visited:
continue
if road not in visited:
visited.append(road)
final_dist[road] = Q[road]
if road in reverse:
if reverse[road]==0.3:
if self.direction == '+':
self.direction=='-'
else:
self.direction=='+'
for neighbour in self.intersctn[road]:
if road==self.end:
starting=self.intersctn[neighbour][road]
ending=self.endPoint
else:
starting=self.intersctn[road][neighbour]
ending=self.intersctn[neighbour][road]
if neighbour in visited or starting == ending:
continue
dist,reverseTime= self.calcDist(road, starting,neighbour, ending,self.direction)
totalDist = final_dist[road] + dist
if neighbour not in Q or (totalDist <= Q[neighbour] ):
Q[neighbour] = totalDist
path[neighbour] = road
reverse[neighbour]=reverseTime
distances[neighbour]=dist+reverseTime
if road==self.start:
distances[self.start],reverse[self.start]=self.calcDist(self.start,self.startPoint,neighbour,self.intersctn[self.start][neighbour],self.direction)
if len(visited)==self.noOfRoads:
break
return (distances,path,reverse)
def Dijkstra(G,start,end=None):
Distances = {}
Predecessors = {}
Q = priorityDictionary()
Q[start] = 0
for v in Q:
Distances[v] = Q[v]
if v == end: break
for w in G[v]:
length = Distances[v] + G[v][w]
if w in Distances:
if length < Distances[w]:
raise ValueError, "Found a better path to a final vertex"
elif w not in Q or length < Q[w]:
Q[w] = length
Predecessors[w] = v
return (Distances,Predecessors)
