listqueue.py

#-*-coding:utf-8-*-
#数组实现
class Queue():
 def __init__(self):
 self.entries = [] #表示队列内的参数
 self.length = 0 #表示队列的长度
 self.front=0 #表示队列头部位置
 def enqueue(self, item):#入队列
 self.entries.append(item)
 self.length = self.length + 1 #队列长度增加 1
 def dequeue(self):#出队列
 self.length = self.length - 1 #队列的长度减少 1
 dequeued = self.entries[self.front] #队首元素为dequeued
 self.front-=1 #队首的位置减少1
 self.entries = self.entries[self.front:] #更新队列
 return dequeued
 def peek(self):#获取队列第一个元素
 return self.entries[0]
if __name__ == "__main__":
 q=Queue()
 q.enqueue(7)
 q.enqueue(89)
 print(q.peek())#7
 print(q.dequeue())#7
 print(q.peek())#89