循环链式队列python

循环链式队列是一种特殊的线性数据结构，它将链表的头结点指向尾节点，形成一个闭环，这样可以避免在队列满时需要频繁移动元素的问题。在Python中，我们可以手动实现一个简单的循环链式队列，例如：

class Node:
    def __init__(self, data=None):
        self.data = data
        self.next = None

class CircularQueue:
    def __init__(self, capacity):
        self.capacity = capacity
        self front = self.rear = None

    def is_empty(self):
        return self.front is None

    def is_full(self):
        return (self.rear + 1) % self.capacity == self.front

    def enqueue(self, item):
        if self.is_full():
            print("Queue is full.")
            return
        new_node = Node(item)
        if self.is_empty():
            self.front = self.rear = new_node
        else:
            self.rear.next = new_node
            self.rear = new_node
            self.rear.next = self.front

    def dequeue(self):
        if self.is_empty():
            print("Queue is empty.")
            return
        removed_data = self.front.data
        if self.front == self.rear:
            self.front = self.rear = None
        else:
            self.front = self.front.next
        return removed_data

# 使用示例
queue = CircularQueue(5)
queue.enqueue(1)
queue.enqueue(2)
queue.enqueue(3)
print(queue.dequeue())  # 输出: 1
print(queue.dequeue())  # 输出: 2