def dijkstra(aGraph, start):
pq = PriorityQueue()
start.set_distance(0)
pq.build_heap([(v, v.get_distance()) for v in aGraph])
while not pq.is_empty():
current_vert = pq.dequeue()[0]
for next_vert in current_vert.get_connections():
new_dist = current_vert.get_distance() + current_vert.get_weight(
next_vert)
if new_dist < next_vert.get_distance():
next_vert.set_distance(new_dist)
next_vert.set_pred(current_vert)
pq.decrease_priority(next_vert, new_dist)
def prim(aGraph, start):
pq = PriorityQueue()
for v in aGraph:
v.set_distance(maxsize)
v.set_pred(None)
start.set_distance(0)
pq.build_heap([(v, v.get_distance()) for v in aGraph])
while not pq.is_empty():
current_vert = pq.dequeue()[0]
for next_vert in current_vert.get_connections():
new_cost = current_vert.get_weight(next_vert)
if next_vert in pq and new_cost < next_vert.get_distance():
next_vert.set_distance(new_cost)
next_vert.set_pred(current_vert)
pq.decrease_priority(next_vert, new_cost)
