在循环队列中，我们使用一个数组和两个指针（head 和 tail）。 head 表示队列的起始位置，tail 表示队列的结束位置。
class MyCircularQueue:
def __init__(self, k: int):
"""
Initialize your data structure here. Set the size of the queue to be k.
"""
self.queue = [0] * k
self.head = -1
self.tail = -1
self.size = k
def enQueue(self, value: int) -> bool:
"""
Insert an element into the circular queue. Return true if the operation is successful.
"""
if self.isFull():
return False
if self.isEmpty():
self.head = 0
self.tail = (self.tail + 1) % self.size
self.queue[self.tail] = value
return True
def deQueue(self) -> bool:
"""
Delete an element from the circular queue. Return true if the operation is successful.
"""
if self.isEmpty():
return False
if self.head ==self.tail:
self.head = -1
self.tail = -1
return True
# 从头部移除元素
self.head = (self.head + 1) % self.size
return True
def Front(self) -> int:
"""
Get the front item from the queue.
"""
if self.isEmpty():
return -1
else:
return self.queue[self.head]
def Rear(self) -> int:
"""
Get the last item from the queue.
"""
if self.isEmpty():
return -1
else:
return self.queue[self.tail]
def isEmpty(self) -> bool:
"""
Checks whether the circular queue is empty or not.
"""
return self.head == -1
def isFull(self) -> bool:
"""
Checks whether the circular queue is full or not.
"""
return (self.tail + 1) % self.size ==self.head
