def scan(graph, search, vertex):
"""
Args:
search: La estructura de busqueda
vertex: El vertice destino
Returns:
El costo total para llegar de source a
vertex. Infinito si no existe camino
Raises:
Exception
"""
try:
map.put(search['marked'], vertex, True)
edges = g.adjacentEdges(graph, vertex)
for edge in lt.iterator(edges):
w = e.other(edge, vertex)
if (not map.get(search['marked'], w)['value']):
if (e.weight(edge) < map.get(search['distTo'], w)['value']):
map.put(search['distTo'], w, e.weight(edge))
map.put(search['edgeTo'], w, edge)
if (pq.contains(search['pq'], w)):
pq.decreaseKey(search['pq'], w,
map.get(search['distTo'], w)['value'])
else:
pq.insert(search['pq'], w,
map.get(search['distTo'], w)['value'])
return search
except Exception as exp:
error.reraise(exp, 'bellman:disto')
def relax(search, edge):
"""
Relaja el peso de los arcos del grafo con la
nueva de un nuevo arco
Args:
search: La estructura de busqueda
edge: El nuevo arco
Returns:
El grafo con los arcos relajados
Raises:
Exception
"""
try:
v = e.either(edge)
w = e.other(edge, v)
visited_v = map.get(search['visited'], v)['value']
visited_w = map.get(search['visited'], w)['value']
distw = visited_w['distTo']
distv = visited_v['distTo'] + e.weight(edge)[0]
if (visited_w is None) or (distw > distv):
distow = visited_v['distTo'] + e.weight(edge)[0]
map.put(search['visited'], w, {
'marked': True,
'edgeTo': edge,
'distTo': distow
})
if iminpq.contains(search['iminpq'], w):
iminpq.decreaseKey(search['iminpq'], w, distow)
else:
iminpq.insert(search['iminpq'], w, distow)
return search
except Exception as exp:
error.reraise(exp, 'dks:relax')
def test_insert(iminpq):
iminpq = pq.decreaseKey(iminpq, 'A', 1)
key = pq.min(iminpq)
assert key == 'A'
iminpq = pq.increaseKey(iminpq, 'A', 12)
key = pq.min(iminpq)
assert key == 'D'
def addConnection(bikes, origin, destination, duration):
edge = gr.getEdge(bikes["grafo"], origin, destination)
if edge is None:
gr.addEdge(bikes["grafo"], origin, destination, duration)
else:
initial = edge["weight"]
edge["weight"] = ((int(initial) + int(duration)) / 2)
llegada = gr.indegree(bikes["grafo"], destination)
salida = gr.outdegree(bikes["grafo"], origin)
llegadad = gr.indegree(bikes["grafo"], destination)
salidad = salida = gr.outdegree(bikes["grafo"], origin)
oruse = salida + llegadad
desuse = llegada + salidad
llegadainv = 1 / llegada
salidainv = 1 / salida
iminpq.increaseKey(bikes["topuso"], destination, desuse)
iminpq.increaseKey(bikes["topuso"], origin, oruse)
iminpq.decreaseKey(bikes["topllegada"], destination, llegadainv)
iminpq.decreaseKey(bikes["topsalida"], origin, salidainv)
return bikes