def process(self):
while self._has_augmenting_path(self._source, self._sink):
while True:
common.fill_with_value(self._blocked, False)
delta = self._send_flow(float('inf'), self._source, self._sink,
self._blocked)
self._flow += delta
if delta == 0:
break
print('flow: {0}'.format(self._flow))
def _has_augmenting_path(self, s: int, t: int):
common.fill_with_value(self._levels, -1)
q = queue.Queue()
q.put(s)
self._levels[s] = 0
while not q.empty():
v = q.get()
for edge in self._graph.adj(v):
w = edge.other(v)
if self._levels[w] < 0 and edge.residual_capacity_to(w) > 0:
self._levels[w] = self._levels[v] + 1
q.put(w)
return self._levels[t] >= 0
def _has_augmenting_path(self, s: int, t: int):
common.fill_with_value(self._edge_to, None)
common.fill_with_value(self._marked, False)
q = queue.Queue()
q.put(s)
self._marked[s] = True
while not q.empty():
v = q.get()
for edge in self._graph.adj(v):
w = edge.other(v)
if edge.residual_capacity_to(w) > 0 and not self._marked[w]:
self._edge_to[w] = edge
self._marked[w] = True
q.put(w)
return self._marked[t]
def _recompute_heights(self):
print('recompute_heights')
common.fill_with_value(self._visited, False)
common.fill_with_value(self._heights, 2 * self._graph.vertices())
self._heights[self._sink] = 0
self._heights[self._source] = self._graph.vertices()
self._visited[self._sink] = True
self._visited[self._source] = True
q = queue.Queue()
q.put(self._sink)
self._process_queue_till_empty(q)
q.put(self._source)
self._process_queue_till_empty(q)
self._relabel_counter = 0