def pq_sort(self, test_array):
pq = PriorityQueue()
for x in test_array:
pq.insert(x)
pq_size = pq.size()
return [pq.extract_min() for x in range(pq_size)]
def test_size_remove(self):
pq = PriorityQueue()
for i in range(100):
pq.insert(i)
for i in range(100):
pq.extract_min()
self.assertEqual(pq.size(), 0)
def Dijkstra(g,gn,s,d):
#initialization
dist = {}
prev = {}
Q = PriorityQueue()
# print(g["home"].keys())
#출발노드 s는 자신까지의 거리가 0이고 자신의 predecessor
dist[s] = 0
prev[s] = None
#다른 노드들은 모두 거리를 infinity로 설정하고 predecessor는 일단 None으로 설정하고
'''for n in g:
dist[n[0]] = float('inf')
prev[n[0]] = None
dist[n[1]] = float('inf')
prev[n[1]] = None
'''
#그러면서 PQ에다가 노드들을 넣어줍니다.
for n in g.keys():
if n != s :
dist[n] = float('inf')
prev[n] = None
if n in g[s].keys():
dist[n] = float('inf')
prev[n] = None
Q.insert(dist[n],n) # n이 우선순위 dist가 value
#PQ가 빌때까지 계속 루프를 돌면서,
while Q.size() > 0:
p,u = Q.pop() #현재까지 가장 짧은 거리를 갖고 있는 노드를 pop
#꺼낸 노드의 각 이웃들까지의 거리를 현재 자신까지의 minimum cost와 더한 후
#이웃들이 가지고 있는 거리보다 작으면 이것으로 업데이트 시키고 다시 PQ에 넣거나 update합니다
#pd insert 기능에 포함되어 있다고 한다.
'''for v in g[u].keys():
# alt = dist[u] + g[u][v].get('weight',1)
alt = dist[u] + g[u][v]
if alt < dist[v]:
dist[v] = alt
prev[v] = u
Q.insert(dist[v],v) #for v in g.neighbors(u):
'''
for v in g[u].keys():
# alt = dist[u] + g[u][v].get('weight',1)
alt = dist[u] + int(g[u][v][0]) # distance 계산에 쓰임.
alt2 = dist[u] + int(gn[u][v][0]) # 경로 선택에 쓰임.
if alt2 < dist[v]:
dist[v] = alt
prev[v] = u
Q.insert(dist[v],v)
return dist, prev
def get_huffman_tree(frequency_lst):
frequency_lst = Counter(s)
pq = PriorityQueue()
for char, freq in frequency_lst:
pq.insert(freq, TreeNode(char))
while pq.size() > 1:
freq1, node1 = pq.delete_min()
freq2, node2 = pq.delete_min()
internal_node = TreeNode(node1.val + node2.val, node1, node2)
pq.insert(freq1 + freq2, internal_node)
_, root = pq.delete_min()
return get_code(root)
class MaxHeap(object):
def __init__(self, lst=[]):
lst = [(-prio, ele) for (prio, ele) in lst]
self.maxHeap = PriorityQueue(lst)
def insert(self, priority, ele):
self.maxHeap.insert(-priority, ele)
def delete_max(self):
prio, ele = self.maxHeap.delete_min()
return -prio, ele
def get_max(self):
prio, ele = self.maxHeap.get_min()
return -prio, ele
def size(self):
return self.maxHeap.size()
class InformedSearch(Search):
"""
Implement this.
"""
def __init__(self, initial_state, goal_state, verbose=False):
self.node_expansions = 0
self.unique_states = {}
self.unique_states[initial_state.dictkey()] = True
self.q = PriorityQueue()
self.goal_state = goal_state
self.q.enqueue(InformedNode(initial_state, None, 0, self.goal_state))
self.verbose = verbose
solution = self.execute()
if solution is None:
print("Search failed")
else:
self.showPath(solution)
def execute(self):
while not self.q.empty():
current = self.q.dequeue()
self.node_expansions += 1
if self.goal_state.equals(current.state):
return current
else:
successors = current.state.applyOperators()
for next_state in successors:
if next_state.dictkey() not in self.unique_states.keys():
n = InformedNode(next_state, current,
current.depth + 1, self.goal_state)
self.q.enqueue(n)
self.unique_states[next_state.dictkey()] = True
if self.verbose:
print("Expanded:", current)
print("Number of successors:", len(successors))
print("Queue length: ", self.q.size())
print("-------------------------------")
return None
def get_expansions(self):
return self.node_expansions
def test_size_insert(self):
pq = PriorityQueue()
for i in range(100):
self.assertEqual(pq.size(), i)
pq.insert(i)
def test_size_initial(self):
pq = PriorityQueue()
self.assertEqual(pq.size(), 0)
def test_size_insert(self):
pq = PriorityQueue()
for i in range(100):
self.assertEqual(pq.size(), i)
pq.insert(i)
def test_size_initial(self):
pq = PriorityQueue()
self.assertEqual(pq.size(), 0)
