def quick_shortest(graph):
N = graph.N-1
distances = {}
previous = {}
previous[0] = None
distances[N] = 0.0
for idx in xrange(N-1,-1,-1):
Q = priorityDictionary()
for x in graph[idx]:
Q[x] = graph[idx][x] + distances[x]
small = Q.smallest()
previous[idx] = small
distances[idx] = Q[small]
# get path from previous 21/08/13 09:10:14
paths = []
paths.append(0)
start = 0
while start < N:
paths.append(previous[start])
start = previous[start]
return (distances, paths)
def dijkstra(graph, node_start, node_end=None):
distances = {}
previous = {}
Q = priorityDictionary()
for v in graph:
distances[v] = graph.INFINITY
previous[v] = graph.UNDEFINDED
Q[v] = graph.INFINITY
distances[node_start] = 0
Q[node_start] = 0
for v in Q:
if v == node_end: break
for u in graph[v]:
cost_vu = distances[v] + graph[v][u]
if cost_vu < distances[u]:
distances[u] = cost_vu
Q[u] = cost_vu
previous[u] = v
if node_end != None:
return {
'cost': distances[node_end],
'path': path(previous, node_start, node_end)
}
else:
return (distances, previous)
def dijkstra(graph, node_start, node_end=None):
distances = {}
previous = {}
Q = priorityDictionary()
for v in graph:
distances[v] = graph.INFINITY
previous[v] = graph.UNDEFINDED
Q[v] = graph.INFINITY
distances[node_start] = 0
Q[node_start] = 0
for v in Q:
if v == node_end: break
for u in graph[v]:
cost_vu = distances[v] + graph[v][u]
if cost_vu < distances[u]:
distances[u] = cost_vu
Q[u] = cost_vu
previous[u] = v
if node_end!=None:
return {'cost': distances[node_end],
'path': path(previous, node_start, node_end)}
else:
return (distances, previous)
def dp_graph(graph, node_start, node_end=None):
N = graph.N
distances = {}
previous = {}
previous[node_start] = None
for idx in xrange(0, node_start + 1, 1):
distances[idx] = 0.0
for idx in xrange(node_start + 1, N, 1):
Q = priorityDictionary()
for x in graph[idx]:
Q[x] = distances[x] + graph[idx][x]
small = Q.smallest()
if small < node_start:
previous[idx] = node_start
else:
previous[idx] = Q.smallest()
distances[idx] = Q[small]
if node_end:
return {
'cost': distances[node_end],
'path': path(previous, node_start, node_end)
}
else:
return (distances, previous)
def dijkstra(g, length_graph, node_start):
distances = {}
Q = priorityDictionary()
visited = []
for v in g:
distances[v] = g.INFINITY
Q[v] = g.INFINITY
distances[node_start] = 0
Q[node_start] = 0
for v in Q:
visited.append(v)
if len(visited) == length_graph:
break
for u in g[v]:
if u in visited:
continue
cost_vu = distances[v] + g[v][u]
if cost_vu < distances[u]:
distances[u] = cost_vu
Q[u] = cost_vu
return distances
def dp_graph(graph, node_start, node_end=None):
N = graph.N
distances = {}
previous = {}
previous[node_start] = None
for idx in xrange(0, node_start+1, 1):
distances[idx] = 0.0
for idx in xrange(node_start+1,N,1):
Q = priorityDictionary()
for x in graph[idx]:
Q[x] = distances[x] + graph[idx][x]
small = Q.smallest()
if small < node_start:
previous[idx] = node_start
else:
previous[idx] = Q.smallest()
distances[idx] = Q[small]
if node_end:
return {'cost': distances[node_end],
'path': path(previous, node_start, node_end)}
else:
return (distances, previous)
def shortest_path(self, graph, node_start, node_end=UNDEFINED):
INFINITY = 999
UNDEFINED = None
distances = {}
previous = {}
Q = priorityDictionary()
# Q = {}
# print(type(INFINITY))
for v in graph:
distances[v] = INFINITY
previous[v] = UNDEFINED
Q[v] = INFINITY
distances[node_start] = 0
Q[node_start] = 0
for v in Q:
if v == node_end:
break
for u in graph[v]:
dist_vu = distances[v] + graph[v][u]
if dist_vu < distances[u]:
distances[u] = dist_vu
Q[u] = dist_vu
previous[u] = v
if node_end:
return {
'dist': distances[node_end],
'path': self.path(previous, node_start, node_end)
}
else:
return (distances, previous)
def Dijkstra(self, node_start, node_end=None):
###
# Dijkstra's algorithm
# only use part of the the graph, i.e. aGraph (in the approximity of startPt
# and endPt) to build Dict gDict in order to reduce complexity
###
distances = {}
previous = {}
Q = priorityDictionary()
for v in self.vertList:
distances[v] = maxVal
previous[v] = None
Q[v] = maxVal
distances[node_start] = 0
Q[node_start] = 0
for v in Q:
if v == node_end: break
for u in self.vertList[v].getConnections():
cost_vu = distances[v] + self.vertList[v].connectedTo[u][0]
if u in self and cost_vu < distances[u]:
distances[u] = cost_vu
Q[u] = cost_vu
previous[u] = v
if node_end:
return {'dist': distances[node_end],
'path': self.path(previous, node_start, node_end)}
else:
return (distances, previous)
def dijkstra(g, length_graph, node_start):
distances = {}
Q = priorityDictionary()
visited = []
for v in g:
distances[v] = g.INFINITY
Q[v] = g.INFINITY
distances[node_start] = 0
Q[node_start] = 0
for v in Q:
visited.append(v)
if len(visited) == length_graph:
break
for u in g[v]:
if u in visited:
continue
cost_vu = distances[v] + g[v][u]
if cost_vu < distances[u]:
distances[u] = cost_vu
Q[u] = cost_vu
return distances
def dijkstra(graph, node_start, node_end=None, visited=[]):
distances = {}
previous = {}
Q = priorityDictionary()
visited_copy = deepcopy(visited)
for v in graph:
distances[v] = graph.INFINITY
previous[v] = graph.UNDEFINDED
Q[v] = graph.INFINITY
'''
distances[v] = graph.INFINITY
previous[v] = graph.UNDEFINDED
Q[v] = graph.INFINITY
'''
distances[node_start] = 0
Q[node_start] = 0
for v in Q:
visited_copy.append(v)
if v == node_end: break
for u in graph[v]:
if u in visited_copy:
continue
cost_vu = 0
if distances[v] > graph[v][u]:
cost_vu = distances[v]
else:
cost_vu = graph[v][u]
if cost_vu < distances[u]:
distances[u] = cost_vu
Q[u] = cost_vu
previous[u] = v
'''
cost_vu = distances[v] + graph[v][u]
if cost_vu < distances[u]:
distances[u] = cost_vu
Q[u] = cost_vu
previous[u] = v
'''
if node_end != None:
return {'cost': distances[node_end],
'path': path(previous, node_start, node_end)}
else:
return (distances, previous)
def dijkstra(graph, node_start, node_end=None, visited=[]):
distances = {}
previous = {}
Q = priorityDictionary()
visited_copy = deepcopy(visited)
for v in graph:
distances[v] = graph.INFINITY
previous[v] = graph.UNDEFINDED
Q[v] = graph.INFINITY
'''
distances[v] = graph.INFINITY
previous[v] = graph.UNDEFINDED
Q[v] = graph.INFINITY
'''
distances[node_start] = 0
Q[node_start] = 0
for v in Q:
visited_copy.append(v)
if v == node_end: break
for u in graph[v]:
if u in visited_copy:
continue
cost_vu = 0
if distances[v] > graph[v][u]:
cost_vu = distances[v]
else:
cost_vu = graph[v][u]
if cost_vu < distances[u]:
distances[u] = cost_vu
Q[u] = cost_vu
previous[u] = v
'''
cost_vu = distances[v] + graph[v][u]
if cost_vu < distances[u]:
distances[u] = cost_vu
Q[u] = cost_vu
previous[u] = v
'''
if node_end != None:
return {
'cost': distances[node_end],
'path': path(previous, node_start, node_end)
}
else:
return (distances, previous)
def dijkstra(graph, node_start, node_end=None):
distances = {}
previous = {}
Q = priorityDictionary()
for v in graph:
for u in v.neighbors:
distances[u] = inf
previous[u] = None
Q[u] = inf
distances[node_start] = 0
Q[node_start] = 0
for v in Q:
if v == node_end: break
v_node = graph.get_node(v)
if not v_node.is_active():
continue
for u in v_node.neighbors:
if not graph.get_node(u).is_active():
continue
edge = graph.get_edge(v,u)
if not edge.is_active():
continue
cost_vu = distances[v] + edge.data.length
if cost_vu < distances[u]:
distances[u] = cost_vu
Q[u] = cost_vu
previous[u] = v
if node_end:
return {'cost': distances[node_end],
'path': path(previous, node_start, node_end),
'distances': distances}
else:
return (distances, previous)
def dijkstra3(graph, node_start, node_end=None, all_paths=None):
distances = {}
previous = {}
Q = priorityDictionary()
for v in graph:
distances[v] = DiGraph.INFINITY
previous[v] = DiGraph.UNDEFINDED
Q[v] = DiGraph.INFINITY
for u in graph[v]:
if u in distances:
continue
distances[u] = DiGraph.INFINITY
distances[node_start] = 0
Q[node_start] = 0
for v in Q:
if v == node_end: break
if not graph[v]:
continue
for u in graph[v]:
newcost = graph[v][u]
for w in range(0, len(all_paths)):
if u == all_paths[w]:
newcost = 100
cost_vu = distances[v] + newcost
if cost_vu < distances[u]:
distances[u] = cost_vu
Q[u] = cost_vu
previous[u] = v
if node_end:
return {
'cost': distances[node_end],
'path': path(previous, node_start, node_end)
}
else:
return (distances, previous)
def dijkstra(graph, node_start, node_end=None):
#print"graph",graph
#print node_start, node_end
#node_start = node_start.encode('utf-8')
#node_end = node_end.encode('utf-8')
distances = {}
previous = {}
Q = priorityDictionary()
for v in graph:
##print "-%s-"%v
distances[v] = DiGraph.INFINITY
previous[v] = DiGraph.UNDEFINDED
Q[v] = DiGraph.INFINITY
for u in graph[v]:
if u in distances:
continue
distances[u] = DiGraph.INFINITY
distances[node_start] = 0
Q[node_start] = 0
for v in Q:
if v == node_end: break
if not graph[v]:
continue
for u in graph[v]:
cost_vu = distances[v] + graph[v][u]
if cost_vu < distances[u]:
distances[u] = cost_vu
Q[u] = cost_vu
previous[u] = v
if node_end:
return {'cost': distances[node_end],
'path': path(previous, node_start, node_end)}
else:
return (distances, previous)
def quick_shortest(graph):
N = graph.N - 1
distances = {}
previous = {}
previous[0] = None
distances[N] = 0.0
for idx in xrange(N - 1, -1, -1):
Q = priorityDictionary()
for x in graph[idx]:
Q[x] = graph[idx][x] + distances[x]
small = Q.smallest()
previous[idx] = small
distances[idx] = Q[small]
# get path from previous 21/08/13 09:10:14
paths = []
paths.append(0)
start = 0
while start < N:
paths.append(previous[start])
start = previous[start]
return (distances, paths)