class CircularQueue: def __init__(self, cap=10): self.capacity = cap # 循环队列的容量 self.entry = [None for x in range(0, self.capacity)] self.front = 0 self.rear = self.capacity - 1 def serve(self): # 循环队列出队操作 if _________: # 判断循环队列是否为空 return None else: item = self.entry[self.front] # 保存将要出队的元素 ________ # 修改头指针 return item

class CircularQueue:

    def __init__(self, cap=10):

        self.capacity = cap  # 循环队列的容量

        self.entry = [None for x in range(0, self.capacity)]

        self.front = 0

        self.rear = self.capacity - 1

    def serve(self):  # 循环队列出队操作

        if _________:  # 判断循环队列是否为空

            return None

        else:

            item = self.entry[self.front]  # 保存将要出队的元素

            ________  # 修改头指针

            return item