Define a queue:
class Queue:
def __init__(self) -> None:
self.items = []
def isEmpty(self):
return self.items == []
def enqueue(self, item):
# 入队在开始
self.items.insert(0, item)
def dequeue(self):
# 出队在最后
return self.items.pop()
def size(self):
return len(self.items)
q = Queue()
q.isEmpty()
True
q.enqueue('dog')
q.enqueue(4)
q.size()
1
q.enqueue(8.4)
Pass the Potatoes, or Toss the Handkerchief, or Joseph's Ring
## 传土豆游戏
def hotPotato(namelist, num):
simqueue = Queue()
for name in namelist:
simqueue.enqueue(name)
while simqueue.size() > 1:
# 每次第7個人出隊,問最後出隊列的是誰
for i in range(num):
simqueue.enqueue(simqueue.dequeue())
simqueue.dequeue()
return simqueue.dequeue()
namelist = ['Bill','David','Susan','Jane','Kent','Brad']
num = 7
hotPotato(namelist, num)
'Susan'
#like the print job queue mentioned above
class Printer:
def __init__(self,ppm) -> None:
self.pagerate = ppm
self.currentTask = None
self.timeRemaining = 0
def tick(self):
if self.currentTask != None:
self.timeRemaining = self.timeRemaining - 1
if self.timeRemaining <= 0:
self.currentTask = None
def busy(self):
if self.currentTask!=None:
return True
else:
return False
def startNext(self, newtask):
self.currentTask = newtask
self.timeRemaining = newtask.getPage() * 60 / self.pagerate
import random
class Task:
def __init__(self, time) -> None:
self.timestamp = time
self.pages = random.randrange(1, 21)
def getStamp(self):
return self.timestamp
def getPages(self):
return self.pages
def waitTime(self, currenttime):
return currenttime - self.timestamp
def newPrintTask():
num = random.randrange(1, 181)
if num == 180:
return True
else:
return False
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 newPrintTask():
num = random.randrange(1, 181)
if num == 180:
return True
else:
return False