def newDijkstra(graph, s):
"""
Crea una busqueda Dijkstra para un digrafo y un vertice origen
"""
prime = nextPrime (g.numVertex(graph) * 2)
search = {'graph':graph, 's':s, 'visitedMap':None, 'minpq':None}
search['visitedMap'] = map.newMap(numelements=prime, maptype='PROBING', comparefunction=graph['comparefunction'])
vertices = g.vertices (graph)
itvertices = it.newIterator (vertices)
while (it.hasNext (itvertices)):
vert = it.next (itvertices)
map.put (search['visitedMap'], vert, {'marked':False,'edgeTo':None,'distTo':math.inf})
map.put(search['visitedMap'], s, {'marked':True,'edgeTo':None,'distTo':0})
pq = minpq.newIndexMinPQ(g.numVertex(graph), comparenames)
search['minpq'] = pq
minpq.insert(search['minpq'], s, 0)
while not minpq.isEmpty(search['minpq']):
v = minpq.delMin(pq)
if not g.containsVertex(graph,v):
raise Exception("Vertex ["+v+"] is not in the graph")
else:
adjs = g.adjacentEdges(search['graph'],v)
adjs_iter = it.newIterator (adjs)
while (it.hasNext(adjs_iter)):
w = it.next (adjs_iter)
relax(search, w)
# obtener los enlaces adjacentes de v
# Iterar sobre la lista de enlaces
# Relajar (relax) cada enlace
return search
def relax(search, edge):
v = e.either(edge)
w = e.other(edge, v)
visited_v = map.get(search['visitedMap'], v)['value']
visited_w = map.get(search['visitedMap'], w)['value']
if visited_w['distTo'] > (visited_v['distTo'] + e.weight(edge)):
distToW = visited_v['distTo'] + e.weight(edge)
map.put(search['visitedMap'], w, {'marked':True,'edgeTo':edge,'distTo':distToW})
if minpq.contains(search['minpq'], w):
minpq.decreasePriority(search['minpq'], w, distToW)
else:
minpq.insert(search['minpq'], w, distToW)