Design_Circular_Queue.py

'''Problem : Design Circular Queue '''

#CODE :

class MyCircularQueue:
	def __init__(self, k: int):
		"""
		Initialize your data structure here. Set the size of the queue to be k.
		"""
		self.queue = [ None ] * k
		self.size = 0
		self.capacity = k
		self.head, self.tail = 0, -1

	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

		self.tail = (self.tail + 1) % self.capacity
		self.queue[self.tail] = value
		self.size += 1
		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

		self.head = (self.head + 1) % self.capacity
		self.size -= 1
		return True
			
	def Front(self) -> int:
		"""
		Get the front item from the queue.
		"""

		return -1 if self.isEmpty() else self.queue[self.head]
			
	def Rear(self) -> int:
		"""
		Get the last item from the queue.
		"""

		return -1 if self.isEmpty() else self.queue[self.tail]

	def isEmpty(self) -> bool:
		"""
		Checks whether the circular queue is empty or not.
		"""
		return self.size <= 0

	def isFull(self) -> bool:
		"""
		Checks whether the circular queue is full or not.
		"""
		return self.size == self.capacity