Leetcode 622 Design Circular Queuepython最小コード

Leetcode 622 Design Circular Queue Python Minimal Code

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''' Design your implementation of the circular queue. The circular queue is a linear data structure in which the operations are performed based on FIFO (First In First Out) principle and the last position is connected back to the first position to make a circle. It is also called 'Ring Buffer'. One of the benefits of the circular queue is that we can make use of the spaces in front of the queue. In a normal queue, once the queue becomes full, we cannot insert the next element even if there is a space in front of the queue. But using the circular queue, we can use the space to store new values. Your implementation should support following operations: MyCircularQueue(k): Constructor, set the size of the queue to be k. Front: Get the front item from the queue. If the queue is empty, return -1. Rear: Get the last item from the queue. If the queue is empty, return -1. enQueue(value): Insert an element into the circular queue. Return true if the operation is successful. deQueue(): Delete an element from the circular queue. Return true if the operation is successful. isEmpty(): Checks whether the circular queue is empty or not. isFull(): Checks whether the circular queue is full or not. Example: MyCircularQueue circularQueue = new MyCircularQueue(3) // set the size to be 3 circularQueue.enQueue(1) // return true circularQueue.enQueue(2) // return true circularQueue.enQueue(3) // return true circularQueue.enQueue(4) // return false, the queue is full circularQueue.Rear() // return 3 circularQueue.isFull() // return true circularQueue.deQueue() // return true circularQueue.enQueue(4) // return true circularQueue.Rear() // return 4 Note: All values will be in the range of [0, 1000]. The number of operations will be in the range of [1, 1000]. Please do not use the built-in Queue library. ''' class MyCircularQueue: def __init__(self, k): ''' Initialize your data structure here. Set the size of the queue to be k. :type k: int ''' self.size = k self.queue = k * [-1] self.head = -1 self.rear = -1 def enQueue(self, value): ''' Insert an element into the circular queue. Return true if the operation is successful. :type value: int :rtype: bool ''' If self.isFull(): # Note when you can't continue to stack return False if self.isEmpty(): self.head = 0 self.rear = (self.rear + 1) % self.size self.queue[self.rear] = value return True def deQueue(self): ''' Delete an element from the circular queue. Return true if the operation is successful. :rtype: bool ''' if self.isEmpty(): return False If self.head == self.rear: # Unstack does not need to really delete the element, just change the head and tail pointer Self.head = -1 # The first and last pointers refer to the same element, and are not -1. There must be only one element at this time. self.rear = -1 return True self.head = (self.head + 1) % self.size return True def Front(self): ''' Get the front item from the queue. :rtype: int ''' return self.queue[self.head] if not self.isEmpty() else -1 def Rear(self): ''' Get the last item from the queue. :rtype: int ''' return self.queue[self.rear] if not self.isEmpty() else -1 def isEmpty(self): ''' Checks whether the circular queue is empty or not. :rtype: bool ''' return self.head == -1 def isFull(self): ''' Checks whether the circular queue is full or not. :rtype: bool ''' Return (self.rear + 1) % self.size == self.head # Consider the loop queue, so go to round # Your MyCircularQueue object will be instantiated and called as such: # obj = MyCircularQueue(k) # param_1 = obj.enQueue(value) # param_2 = obj.deQueue() # param_3 = obj.Front() # param_4 = obj.Rear() # param_5 = obj.isEmpty() # param_6 = obj.isFull()

すべてのLeetcodeトピックが定期的に要約されているわけではありません Github 誰もが批判し、訂正することを歓迎します。