def isReachable(self,u,v):
"""
:param u: Key
:param v: Key
:return:
"""
vertList=self.getVertices()
assert(u in vertList and v in vertList)
start=self.getVertex(u)
end=self.getVertex(v)
start.setDistance(0)
start.setPred(None)
vertQueue=Queue()
vertQueue.enqueue(start)
while(vertQueue.size()!=0):
currentVert=vertQueue.dequeue()
if currentVert.getId()==end.getId():
return True
for nbr in currentVert.getConnections():
if nbr.getColor()=="white":
nbr.setColor('gray')
nbr.setPred(currentVert)
nbr.setDistance(currentVert.getDistance()+1)
vertQueue.enqueue(nbr)
currentVert.setColor('black')
return False
def simulation(numSeconds, tasksPerMinute):
worker1 = Worker(2)
worker2 = Worker(3)
worker3 = Worker(4)
team = Team(worker1, worker2, worker3)
taskQueue = Queue()
waitingtimes = []
for currentSecond in range(numSeconds):
if newTask():
task = Task(currentSecond)
taskQueue.enqueue(task)
if (not team.allBusy()) and (not taskQueue.isEmpty()):
nextTask = taskQueue.dequeue()
team.assignTask(nextText())
waitingtimes.append(nexttask.waitTime(currentSecond))
team.assignTask()
team.tick()
averageWait = sum(waitingtimes) #/len(waitingtimes)
print("Average Wait %6.2f secs %3d tasks remaining." %
(averageWait, taskQueue.size()))
def bfs(self, adj_node):
adj_node.color = Color.gray
adj_node.parent_node = None
adj_node.parent_distance = 0
node_queue = Queue()
node_queue.enqueue(adj_node)
while node_queue.size() > 0:
adj_node = node_queue.dequeue()
if self.found:
break
for node_tup in adj_node.child_nodes:
vertex = node_tup[0]
assert isinstance(vertex, Node)
if vertex.color is Color.white:
vertex.color = Color.gray
vertex.parent_distance = int(node_tup[1])
vertex.parent_node = adj_node
node_queue.enqueue(vertex)
if vertex.name.strip().lower() == self.destination:
self.found = True
self.__searched_list__.append(vertex)
break
adj_node.color = Color.black
def transpose(self):
for aVertex in self:
aVertex.setColor('white')
for key in self.vertices:
start = self.vertices[key]
break
vertQueue = Queue()
vertQueue.enqueue(start)
while vertQueue.size() > 0:
currentVert = vertQueue.dequeue()
toDel = []
for nbr in currentVert.getConnections():
# here is the key
if currentVert.connectedTo[nbr] != -1:
nbr.connectedTo[currentVert] = -1
toDel.append(nbr)
if nbr.getColor() == 'white':
vertQueue.enqueue(nbr)
for vertex in toDel:
if currentVert.connectedTo[vertex] == 0:
del currentVert.connectedTo[vertex]
currentVert.setColor('black')
def simulateOneServer(file_name):
import pandas as pd
df = pd.read_csv(file_name, index_col=0, names = ['currentSecond', 'task', 'Time'])
df2 = df.reset_index()
server = Server()
requestQueue = Queue()
waitingtimes = []
starttime = df2['currentSecond'][0]
for x in range(len(df2)):
task = Task(df2['Time'][x])
requestQueue.enqueue(task)
for x in range(len(df2)):
endtime = starttime + df2['Time'][x]
starttime = endtime
nexttask = requestQueue.dequeue()
waitingtimes.append(nexttask.waitTime(starttime, df2['currentSecond'][x]))
if (not server.busy()) and (not requestQueue.isEmpty()):
server.startNext(nexttask)
server.tick()
averageWait=sum(waitingtimes)/len(waitingtimes)
print("Average Wait %6.2f secs for a single server."%(averageWait))
def hotPotato(names, num):
q = Queue()
for ele in names:
q.enqueue(ele)
while q.size() > 1:
for i in range(num):
q.enqueue(q.dequeue())
q.dequeue()
return q.dequeue()
def hotLine(namelist, num):
simqueue = Queue()
for name in namelist:
simqueue.enqueue(name)
while simqueue.size() > 1:
for i in range(num):
simqueue.enqueue(simqueue.dequeue())
simqueue.dequeue()
return simqueue.dequeue()
def hotpotato(li, n):
simqueue = Queue()
for i in li:
simqueue.enqueue(i)
while simqueue.size() > 1:
for i in range(n):
simqueue.enqueue(simqueue.dequeue())
simqueue.dequeue()
return simqueue.dequeue()
def hotline(namelist, num):
s = Queue()
for name in namelist:
s.enqueue(name)
#return s.size()
while s.size() > 1:
for i in range(num):
s.enqueue(s.dequeue())
s.dequeue()
return s.dequeue()
def test(self, wordStart):
if self.isNoChain(wordStart):
return False
start = self.graph.getVertex(wordStart)
start.setDistance(0)
start.setPred(None)
vrtxQueue = Queue()
vrtxQueue.enqueue(start)
#print(wordStart,end='')
d = defaultdict(list)
while vrtxQueue.size() > 0:
ls = []
current = vrtxQueue.dequeue()
#print(current.getId(),end='')
prev = None
for neighbour in current.getConnections():
if neighbour.getColor() == "white":
neighbour.setColor("gray")
neighbour.setDistance(current.getDistance() + 1)
neighbour.setPred(current)
dist = neighbour.getDistance()
word = neighbour.getId()
d[dist].append(word)
#print("->"+neighbour.getId(),end='')
ls.append(neighbour)
##if neighbour.getId() == wordEnd :
# print("\n\n\t",end='');
#vrtxQueue.enqueue(neighbour)
for i in range(len(ls)):
vrtxQueue.enqueue(ls.pop(0))
current.setColor("black")
outfile = open('Chains.txt', 'a')
print("WORD : " + wordStart, file=outfile)
for length in d.keys():
print(
'----------------------- Length : {} -----------------------'.
format(length),
file=outfile)
self.frequency.setdefault(length, 0)
self.frequency[length] += len(d[length])
for word in d[length]:
vert = self.graph.getVertex(word)
print(vert.getId(), end='', file=outfile)
for count in range(length):
print(" -> " + vert.getPred().getId(),
end='',
file=outfile)
#print()
vert = vert.getPred()
print(file=outfile)
print(file=outfile)
def hot_potato(namelist, num):
queue = Queue()
for name in namelist:
queue.enqueue(name)
while queue.size() > 1:
for _ in range(num):
queue.enqueue(queue.dequeue())
queue.dequeue()
return queue.dequeue()
def hot_potato(name, num=None):
# num = random.randint(1,20)
q = Queue()
for n in name:
q.enqueue(n)
while q.size() > 1:
for _ in range(num):
q.enqueue(q.dequeue())
q.dequeue()
return q.dequeue()
def bfs(g,start):
start.setDistance(0)
start.setPred(None)
vertQueue = Queue()
vertQueue.enqueue(start)
while (vertQueue.size() > 0): currentVert = vertQueue.dequeue()
for nbr in currentVert.getConnections(): if (nbr.getColor() == 'white'):
nbr.setColor('gray')
nbr.setDistance(currentVert.getDistance() + 1)
nbr.setPred(currentVert)
vertQueue.enqueue(nbr)
def hot(names,num): simque = Queue() for name in names: simque.enqueue(name) while simque.size() > 1: for i in range(num): simque.enqueue(simque,dequeue()) simque.dequeue() return simque.dequeue()
def hotPotato(namelist, num):
simqueue = Queue()
for name in namelist:
simqueue.enqueue(name)
while simqueue.size() > 1:
for i in range(num):
simqueue.enqueue(simqueue.dequeue())
simqueue.dequeue()
return simqueue.dequeue()
def hot_potato_simulator(name_list, num):
simple_queue = Queue()
for name in name_list:
simple_queue.enqueue(name)
while simple_queue.size() > 1:
for i in range(num):
simple_queue.enqueue(simple_queue.dequeue())
simple_queue.dequeue()
return simple_queue.dequeue()
def hotPotato(namelist, num):
simqueue = Queue()
for name in namelist:
simqueue.enqueue(name)
while simqueue.size() > 1:
for i in range(random.randrange(1,num)):
simqueue.enqueue(simqueue.dequeue())
simqueue.dequeue()
return simqueue.dequeue()
def hotPotato(namelist, num):
playQueue = Queue()
for name in namelist:
playQueue.enqueue(name)
while playQueue.size() > 1:
for i in range(num):
player = playQueue.dequeue()
playQueue.enqueue(player)
else:
playQueue.dequeue()
return playQueue.dequeue()
def simulateManyServers(file_name, servers):
import pandas as pd
df = pd.read_csv(file_name, index_col=0, names = ['currentSecond', 'task', 'Time'])
df2 = df.reset_index()
df2['RoundRobin'] = ''
networks = servers
orig_networks = servers
for x in range(len(df2)):
df2.at[x, 'RoundRobin'] = networks
networks -= 1
if networks == 0:
networks = orig_networks
for x in range(1, orig_networks + 1):
df3 = df2[df2['RoundRobin']==x]
df3.reset_index(inplace=True)
server = Server()
requestQueue = Queue()
waitingtimes = []
starttime = df3['currentSecond'][0]
for x in range(len(df3)):
task = Task(df3['Time'][x])
requestQueue.enqueue(task)
for x in range(len(df3)):
endtime = starttime + df3['Time'][x]
if df3['currentSecond'][x] > endtime:
starttime = df3['currentSecond'][x]
else:
starttime = endtime
nexttask = requestQueue.dequeue()
waitingtimes.append(nexttask.waitTime(starttime, df3['currentSecond'][x]))
if (not server.busy()) and (not requestQueue.isEmpty()):
server.startNext(nexttask)
# all_waitingtimes.append(averagesubWait)
server.tick()
averageWait=sum(waitingtimes)/len(waitingtimes)
print("Average Wait {} secs for {} servers.".format("{:.2f}".format(round(averageWait,2)), servers))
def bfs(g, start): # --起始顶点作为参数
start.setDistance(0) # --起始顶点的距离
start.setPred(None) # --前驱
vertQueue = Queue()
vertQueue.enqueue(start) # --加入到队列里
while (vertQueue.size() > 0): # --只要队列有顶点
currentVert = vertQueue.dequeue() # -- 取队首作为当前顶点
for nbr in currentVert.getConnections(): # --遍历邻接顶点
if (nbr.getColor() == 'white'): # --邻接顶点是白色的
nbr.setColor('gray') # --将邻接顶点改为灰色
nbr.setDistance(currentVert.getDistance() + 1)
nbr.setPred(currentVert) # --前驱设为当前顶点
vertQueue.enqueue(nbr) # --入队，排到队尾
currentVert.setColor('black') # --for循环结束，将当前顶点设为黑色
def hotPotato(namelist):
simqueue = Queue()
for name in namelist:
simqueue.enqueue(name)
length = len(namelist)
randomor = random.Random()
while simqueue.size() > 1:
num = randomor.randrange(length, 2 * length + 1)
for i in range(num):
simqueue.enqueue(simqueue.dequeue())
simqueue.dequeue()
return simqueue.dequeue()
def hotPotato(namelist):
simqueue = Queue()
for name in namelist:
simqueue.enqueue(name)
while simqueue.size() > 1:
n = random.randint(1, 10)
for i in range(n):
simqueue.enqueue(simqueue.dequeue())
simqueue.dequeue()
return simqueue.dequeue()
def bfs(g, start):
start.setDistance(0)
start.setPred(None)
vertQueue = Queue()
vertQueue.enqueue(start)
while (vertQueue.size() > 0):
currentVert = vertQueue.dequeue()
for nbr in currentVert.getConnections():
if nbr.getColor() == "while":
nbr.setColor("gray")
nbr.setDistance(currentVert.getDistance + 1)
nbr.setPred(currentVert)
vertQueue.enqueue(nbr)
currentVert.setColor("black")
def pathExists(start,end):
vertexQueue=Queue()
vertexQueue.enqueue(start)
while (vertexQueue.size()>0):
item=vertexQueue.dequeue()
if item.getId()==end.getId():
print ("path exists")
return True
else:
for vertex in item.getConnections():
if vertex.getColor()=="white":
vertex.setColor("gray")
vertexQueue.enqueue(vertex)
return False
def bfs(g,start):
start.setDistance(0)
start.setPred(None)#set predecessor to none in order to make this the root of the tree
vertQueue = Queue() #instantiates a queque
vertQueue.enqueue(start) #adds to queque
while (vertQueue.size() > 0):
currentVert = vertQueue.dequeue() #removes first vertex added to the queque
for nbr in currentVert.getConnections(): #gets the vertex's list of connections and loops through the list
if (nbr.getColor() == 'white'):#if unexplored
nbr.setColor('gray')#set to explored
nbr.setDistance(currentVert.getDistance() + 1) #Gives weight/distance of vertex to root. Can be considered layers of tree
nbr.setPred(currentVert)#set predecessor/parent vertex
vertQueue.enqueue(nbr) #places back in queue to explore if vertex has other connections/children
currentVert.setColor('black') #explored
def simulation(total_seconds, pages_per_minute):
queue, wait_times = Queue(), []
printer = Printer(pages_per_minute)
for second in range(total_seconds):
if new_print_task():
queue.enqueue(Task(second))
if not printer.busy() and not queue.is_empty():
task = queue.dequeue()
wait_times.append(task.wait_time(second))
printer.start_next(task)
printer.tick()
print(f'Average Wait {sum(wait_times) / len(wait_times):6.2f} secs {queue.size():2d} tasks remaining.')
def bfs(g, start):
start.setDistance(0)
start.setPred(None)
vertQueue = Queue()
vertQueue.enqueue(start)
while vertQueue.size() > 0:
currentVert = vertQueue.dequeue()
for nbr in currentVert.getConnections():
if nbr.getColor() == "white":
nbr.setColor("gray")
nbr.setDistance(currentVert.getDistance() + 1)
nbr.setPred(currentVert)
vertQueue.enqueue(nbr)
currentVert.setColor("black")
def breadthFirstSearch(start):
start.setDistance(0)
start.setPred(None)
vertQueue = Queue()
vertQueue.enqueue(start)
while vertQueue.size() > 0:
dequeueVert = vertQueue.dequeue()
for neighbor in dequeueVert.getConnections():
if neighbor.getColor() == 'white':
vertQueue.enqueue(neighbor)
neighbor.setColor('gray')
neighbor.setDistance(dequeueVert.getDistance() + 1)
neighbor.setPred(dequeueVert)
dequeueVert.setColor('black')
def bfs(g, start):
start.setDistance(0) #起点的距离设为0
start.setPred(None) #起点没有父节点
vertQueue = Queue() #建立一个队列
vertQueue.enqueue(start) #将起点加入队列中
while (vertQueue.size() > 0): #当队列存在对象时
currentVert = vertQueue.dequeue() #弹出对象并设置为当前节点
"""该迭代阐明了bfs的特点就是把每个邻居都遍历，先完成一层，再往下完成，“广”"""
for nbr in currentVert.getConnections(): #搜索当前节点的所有邻居
if (nbr.getColor() == 'white'): #如果邻居x是白色的（即待搜索）
nbr.setColor('gray') #设为灰色意为正在处理
nbr.setDistance(currentVert.getDistance() + 1) #该邻居距离为当前节点+1
nbr.setPred(currentVert) #该邻居的父节点是当前节点
vertQueue.enqueue(nbr) #队列加入该邻居
def bfs(graph, start):
start.setDistance(0)
start.setPred(None)
vertQueue = Queue() # 利用队列储存邻接的顶点
vertQueue.enqueue(start)
while vertQueue.size() > 0:
currentVert = vertQueue.dequeue() # 对出列的顶点进行操作
for nbr in currentVert.getConnections():
if nbr.getColor(
) == 'white': # 这是pythonds中写好的初始化属性,为白色,代表了此顶点未被探索过
nbr.setColor('gray') # 一个顶点第一次被发现,则被标记为灰色
nbr.setDistance(currentVert.getDistance() + 1)
nbr.setPred(currentVert)
vertQueue.enqueue(nbr)
currentVert.setColor('black') # 一个顶点的所有邻接顶点都被探索后会被标记为黑色
def bfs(g, start):
start.setDistance(0)
start.setPred(None)
vertQueue = Queue()
vertQueue.enqueue(start)
while (vertQueue.size() > 0):
currentVert = vertQueue.dequeue()
for nbr in currentVert.getConnections():
if (nbr.getColor() == 'white'):
nbr.setColor('gray')
nbr.setDistance(currentVert.getDistance() + 1)
nbr.setPred(currentVert)
vertQueue.enqueue(nbr)
currentVert.setColor('black')
print(currentVert) # prints the status of the current visited vertex
def bfs(self, start):
# start.setDistance(0)
start.setPred(None)
vertQueue = Queue()
vertQueue.enqueue(start)
while vertQueue.size() > 0:
currentVert = vertQueue.dequeue()
for nbr in currentVert.getConnections():
# print(nbr)
if nbr.getColor() == 'white':
nbr.setColor('gray')
nbr.setDistance(currentVert.getDistance() + 1)
nbr.setPred(currentVert)
vertQueue.enqueue(nbr)
currentVert.setColor('black')
def bfs(self, start):
# start.setDistance(0)
start.setPred(None)
vertQueue = Queue()
vertQueue.enqueue(start)
while vertQueue.size() > 0:
currentVert = vertQueue.dequeue()
for nbr in currentVert.getConnections():
# print(nbr)
if nbr.getColor() == 'white':
nbr.setColor('gray')
nbr.setDistance(currentVert.getDistance() + 1)
nbr.setPred(currentVert)
vertQueue.enqueue(nbr)
currentVert.setColor('black')
class BFS:
def __init__(self,g,start):
'''
The general algorithm is based on 3 colors
white: not visited not processed
grey: visited but not processed
black: visited and processed
The term processed means all adjacent vertices have been visited.
hence a black node can't have a white neighbor but can have grey or black neighbors
We maintain a queue of nodes to be visited and we run the algo until the queue is empty
Then for every neighbor of the currentNode, we check if it is white,set it to gray,
increment distance by 1,change neighbor's parent to current node and add neighbor to queue
Running time: O(V+E)
:param g: Graph
:param start: starting node or string
:return: None
'''
if not isinstance(start,Vertex) or not isinstance(g,Graph):
raise Exception("Invalid paramaters")
start.setDistance(0)
start.setPred(None)
self.vertQueue=Queue()
self.vertQueue.enqueue(start)
while (self.vertQueue.size()>0):
currentVert=self.vertQueue.dequeue()
for nbr in currentVert.getConnections():
if nbr.getColor()=='white':
nbr.setColor('gray')
nbr.setDistance(currentVert.getDistance()+1)
nbr.setPred(currentVert)
self.vertQueue.enqueue(nbr)
currentVert.setColor('black')
#print((vertQueue))
def traverse(self,y):
'''
following the predecessor links to print out the word ladder.
:param y: Node in a graph
:return: None
'''
x = y
while (x.getPred()):
print(x.getId())
x = x.getPred()
print(x.getId())
def bfs(g, start):
start.setDistance(0)
start.setPred(None)
vertQueue = Queue()
vertQueue.enqueue(start)
while (vertQueue.size() > 0):
current_vertex = vertQueue.dequeue()
for nbr in current_vertex:
if nbr.getColor() == 'white':
nbr.setColor('gray')
nbr.setDistance(current_vertex.getDistance() + 1)
nbr.setPred(current_vertex)
vertQueue.enqueue(nbr)
current_vertex.setColor('black')
def bfs(g,s):
#s = g.getVertex(vertKey)
s.setDistance(0)
s.setPred(None)
s.setColor('gray')
Q = Queue()
Q.enqueue(s)
while (Q.size() > 0):
w = Q.dequeue()
for v in w.getAdj():
print v.id
if(v.getColor() == 'white'):
v.setColor('gray')
v.setDistance(w.getDistance() + 1)
v.setPred(w)
Q.enqueue(v)
w.setColor('black')
def bfs(g,start,searchKey):
vertexQueue=Queue()
start.setDistance(0)
vertexQueue.enqueue(start)
while (vertexQueue.size()>0):
currentVertex=vertexQueue.dequeue()
print currentVertex.getId()
if(searchKey==currentVertex.getId()):
print "distance is",currentVertex.getDistance()
break
for vertex in currentVertex.getConnections():
if (vertex.getColor()=="white"):
vertex.setColor("gray")
print currentVertex.getDistance()
vertex.setDistance(currentVertex.getDistance()+1)
vertexQueue.enqueue(vertex)
currentVertex.setColor("black")
def bfs(g, start):
start.setDistance(0)
start.setPred(None)
vertQueue = Queue()
vertQueue.enqueue(start)
while vertQueue.size() > 0:
currentVert = vertQueue.dequeue()
for nbr in currentVert.getConnections():
if nbr.getColor() == 'white':
# gray means in queue, waiting to be exhausted
nbr.setColor('gray')
nbr.setDistance(currentVert.getDistance() + 1)
nbr.setPred(currentVert)
vertQueue.enqueue(nbr)
# black means it's exhausted
currentVert.setColor('black')
def simulation(numSeconds, pagesPerMinute):
labprinter = Printer(pagesPerMinute)
printQueue = Queue()
waitingtimes = []
for currentSecond in range(numSeconds):
if newPrintTask():
task = Task(currentSecond)
printQueue.enqueue(task)
if (not labprinter.busy()) and \
(not printQueue.isEmpty()):
nexttask = printQueue.dequeue()
waitingtimes.append( \
nexttask.waitTime(currentSecond))
labprinter.startNext(nexttask)
labprinter.tick()
averageWait=sum(waitingtimes)/len(waitingtimes)
print("Average Wait %6.2f secs %3d tasks remaining."\
%(averageWait,printQueue.size()))
def bfs(seed, graph):
""" Finds connected nodes to seeds with given graph
Args:
seed (Vertex): vertex with seed ID
graph (Graph): contains edges from source node to target node
Returns:
list(str(seed ID)): list of connected seeds
"""
seed.setDistance(0)
seed.setPred(None)
vertQueue = Queue()
vertQueue.enqueue(seed)
connected_nodes = []
while (vertQueue.size() > 0):
currentVert = vertQueue.dequeue()
for nbr in currentVert.getConnections():
if (nbr.getColor() == 'white'):
nbr.setColor('gray')
nbr.setDistance(currentVert.getDistance()+1)
nbr.setPred(currentVert)
vertQueue.enqueue(nbr)
connected_nodes.append(nbr.getId())
currentVert.setColor('black')
return connected_nodes
