带尾节点的单链表队列 入队0（1） 出队0（1）
1 #!/usr/bin/env python3 2 3 class QueueUnderflow(ValueError): 4 pass 5 6 class Node(object): 7 def __init__(self, elem, next_=None): 8 self.elem = elem 9 self.next = next_ 10 11 #queue_list 12 class LQueue(object): 13 def __init__(self): 14 self.head = None 15 self.rear = None 16 self.num = 0 17 18 def is_empty(self): 19 return self.head is None 20 21 def count(self): 22 return self.num 23 24 def dequeue(self): 25 p = self.head 26 if not p: 27 raise QueueUnderflow 28 e = p.elem 29 self.head = p.next 30 self.num -= 1 31 return e 32 33 def enqueue(self, elem): 34 p = self.head 35 if not p: 36 self.head = Node(elem, self.head) 37 self.rear = self.head 38 self.num += 1 39 return 40 self.rear.next = Node(elem) 41 self.rear = self.rear.next 42 self.num += 1 43 44 def peek(self): 45 p = self.head 46 if not p: 47 raise QueueUnderflow 48 e = p.elem 49 return e 50 51 def bianli(self): 52 p = self.head 53 li = [] 54 while p: 55 li.append(p.elem) 56 p = p.next 57 return li 58 59 if __name__ == '__main__': 60 lq = LQueue() 61 l = [1,2,3,4,5] 62 for i in l: 63 lq.enqueue(i) 64 print(lq.bianli()) 65 lq.dequeue() 66 print(lq.peek())