1队列（Python实现）

Posted 2021-02-20 Aluosen

# -*- coding:utf-8 -*-
#@Time : 2020/5/1 22:15
#@Author: Aluosen
#@File : Queue.py
#队列的基本方法
class Queue:
    def __init__(self):
        self.items = []
    def isEmpty(self):
        return self.items == []
    def enqueue(self):
        self.items.insert((0,item))
    def dequeue(self):
        return self.items.pop()
    def size(self):
        return len(self.items)

#热土豆问题
def hotPotato(namelist,num):
    simqueue = Queue()
    for name in namelist:
        simqueue.enqueue(name)
    while simqueue.size() > 1:
        for i in range(num):
            #一次传递
            simqueue.enqueue(simqueue.dequeue())
        simqueue.dequeue()
    return simqueue.dequeue()

#打印机任务实现
import random

#打印机
class Printer:
    def __init__(self,ppm):
        self.pagerate = ppm             #打印速度
        self.currentTask = None         #打印任务
        self.timeRemaining = 0          #任务倒计时
    #打印1秒
    def tick(self):
        if self.currentTask != None:
            self.timeRemaining = self.timeRemaining - 1
            if self.timeRemaining <= 0
                self.currentTask = None
    #打印忙
    def busy(self):
        if self.currentTask != None:
            return True
        else:
            return False
    #打印新作业
    def startNext(self,newtask):
        self.currentTask = newtask
        self.timeRemaining = newtask.getPages() * 60 / self.pagerate

#作业
class Task:
    def __init__(self,time):
        self.timestamp = time                       #打印时间戳
        self.pages = random.randrange(1,21)         #打印页数
    def getStamp(self):
        return self.timestamp
    def getPages(self):
        return self.pages
    def waitTime(self,currenttime):
        return currenttime - self.timestamp         #等待时间

def newPrintTask()
    num = random.randrange(1,181)                   #新生成打印作业概率为1/180
    if num == 190:
        return True
    else:
        return False

#模拟
def simulation(numSeconds,pagesPerMinute)
    labprinter = Printer(pagesPerMinute)
    printQueue = Queue()
    waintingtimes = []
    #时间流逝
    for currentSecond in range(numSeconds):
        if newPrintTask():
            task = Task(currentSecond)
            printQueue.enqueue(task)
        if (not labprinter.busy()) and (not printQueue.isEmpty())
            nexttask = printQueue.dequeue()
            waintingtimes.append(nexttask.waitTime(currentSecond))
            labprinter.startNext(nexttask)
        labprinter.tick()
    averageWait = sum(waintingtimes)/len(waintingtimes)
    print(‘Average Wait %6.2f secs %3d task remaining.‘ %(averageWait,printQueue.size()))

#双端队列
class Deque:
    def __init__(self):
        self.items = []
    def isEmpty(self):
        return self.items == []
    def addFront(self,item):
        self.items.append(item)
    def addRear(self,item):
        self.items.insert(0,item)
    def removeFront(self):
        return self.items.pop()
    def removeRear(self):
        return self.items.pop(0)
    def size(self):
        return len(self.items)

#回文词判断
def palchecker(sString):
    chardeque = Deque()
    for ch in aString:
        chardeque.addRear(ch)
    stillEqual = True
    while chardeque.size() > 1 and stillEqual:
        first = chardeque.removeFront()
        last = chardeque.removeRear()
        if first != last:
            stillEqual = False
    return stillEqual