Created
May 16, 2016 04:52
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class Graph(object): | |
def __init__(self): | |
self.g = {} | |
def add(self, vertex1, vertex2, weight): | |
if vertex1 not in self.g: | |
self.g[vertex1] = {} | |
if vertex2 not in self.g: | |
self.g[vertex2] = {} | |
self.g[vertex1][vertex2] = weight | |
self.g[vertex2][vertex1] = weight | |
def has_link(self, v1, v2): | |
return v2 in self[v1] or v1 in self[v2] | |
def edges(self): | |
data = [] | |
for from_vertex, destinations in self.g.items(): | |
for to_vertex, weight in destinations.items(): | |
if (to_vertex, from_vertex, weight) not in data: | |
data.append((from_vertex, to_vertex, weight)) | |
return data | |
def sorted_by_weight(self, desc=False): | |
return sorted(self.edges(), key=lambda x: x[2], reverse=desc) | |
def spanning_tree(self, minimum=True): | |
mst = Graph() | |
parent = {} | |
rank = {} | |
def find_parent(vertex): | |
while parent[vertex] != vertex: | |
vertex = parent[vertex] | |
return vertex | |
def union(root1, root2): | |
if rank[root1] > rank[root2]: | |
parent[root2] = root1 | |
else: | |
parent[root2] = root1 | |
if rank[root2] == rank[root1]: | |
rank[root2] += 1 | |
for vertex in self.g: | |
parent[vertex] = vertex | |
rank[vertex] = 0 | |
for v1, v2, weight in self.sorted_by_weight(not minimum): | |
parent1 = find_parent(v1) | |
parent2 = find_parent(v2) | |
if parent1 != parent2: | |
mst.add(v1, v2, weight) | |
union(parent1, parent2) | |
if len(self) == len(mst): | |
break | |
return mst | |
def __len__(self): | |
return len(self.g.keys()) | |
def __getitem__(self, node): | |
return self.g[node] | |
def __iter__(self): | |
for edge in self.edges(): | |
yield edge | |
def __str__(self): | |
return "\n".join('from %s to %s: %d' % edge for edge in self.edges()) | |
graph = Graph() | |
graph.add('a', 'b', 2) | |
graph.add('a', 'd', 3) | |
graph.add('a', 'c', 3) | |
graph.add('b', 'a', 2) | |
graph.add('b', 'c', 4) | |
graph.add('b', 'e', 3) | |
graph.add('c', 'a', 3) | |
graph.add('c', 'b', 4) | |
graph.add('c', 'd', 5) | |
graph.add('c', 'e', 1) | |
graph.add('d', 'a', 3) | |
graph.add('d', 'c', 5) | |
graph.add('d', 'f', 7) | |
graph.add('f', 'd', 7) | |
graph.add('f', 'e', 8) | |
graph.add('f', 'g', 9) | |
print(graph.spanning_tree()) | |
print() | |
print(graph.spanning_tree(False)) |
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-module(program). | |
-export([start/0]). | |
-define(MAX_CONSUMER, 3). | |
-define(MAX_PRODUCER, 10). | |
-define(ITEMS_PER_PRODUCER, 5). | |
start() -> | |
TaskHandlerPID = spawn(fun() -> task_handler(?MAX_PRODUCER, 0, []) end), | |
spawn_producer(?MAX_PRODUCER, ?ITEMS_PER_PRODUCER, TaskHandlerPID). | |
spawn_producer(NProducer, Repetitions, TaskHandlerPID) -> | |
case NProducer of | |
0 -> | |
ok; | |
_ -> | |
spawn(fun() -> producer(TaskHandlerPID, Repetitions) end), | |
spawn_producer(NProducer - 1, Repetitions, TaskHandlerPID) | |
end. | |
producer(TaskHandlerPID, Repetitions) when Repetitions > 0 -> | |
TaskHandlerPID ! {producer, random:uniform(90) + 10}, | |
producer(TaskHandlerPID, Repetitions - 1); | |
producer(TaskHandlerPID, _) -> | |
TaskHandlerPID ! bye. | |
consumer(TaskHandlerPID, Data) -> | |
io:format("~w~n", [Data * Data]), | |
TaskHandlerPID ! {consumer, ok}. | |
task_handler(NProducer, NConsumer, Items) -> | |
receive | |
bye -> | |
case NProducer of | |
0 -> | |
ok; | |
_ -> | |
task_handler(NProducer - 1, NConsumer, Items) | |
end; | |
{producer, Data} -> | |
case NConsumer of | |
?MAX_CONSUMER -> | |
task_handler(NProducer, NConsumer, lists:append(Items, [Data])); | |
_ -> | |
spawn(fun() -> consumer(self(), Data) end), | |
task_handler(NProducer, NConsumer, Items) | |
end; | |
{consumer, ok} -> | |
case Items of | |
[] -> | |
task_handler(NProducer, NConsumer - 1, Items); | |
[Head|Tail] -> | |
spawn(fun() -> consumer(self(), Head) end), | |
task_handler(NProducer, NConsumer - 1, Tail) | |
end | |
end. |
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