设有一个环形队列,该队列只有一个 队列头指针head,不设队列尾指针,而改置 计数器count用以记录队列中结点的个数. 试编写的代码实现队列的五个运算;A.设置队列的初始空态 B.判定队列是否为空 C.取队列头结点的值给变量x D.将x元素入队 E.删除队列头

可以使用一个数组来实现环形队列。下面是一个简单的示例代码：

class CircularQueue:
    def __init__(self, capacity):
        self.capacity = capacity
        self.queue = [None] * capacity
        self.head = 0
        self.count = 0

    def is_empty(self):
        return self.count == 0

    def get_front(self):
        if self.is_empty():
            raise Exception("Queue is empty")
        return self.queue[self.head]

    def enqueue(self, item):
        if self.count == self.capacity:
            raise Exception("Queue is full")
        tail = (self.head + self.count) % self.capacity
        self.queue[tail] = item
        self.count += 1

    def dequeue(self):
        if self.is_empty():
            raise Exception("Queue is empty")
        front = self.queue[self.head]
        self.queue[self.head] = None
        self.head = (self.head + 1) % self.capacity
        self.count -= 1
        return front