#622

Design Circular Queue

specialist · 810 · lc medium +31 · 54.1% accepted · 3,835 likes · top 46%

Description

Implement a circular queue (also known as a Ring Buffer) with fixed capacity k using FIFO ordering where the tail wraps back around to the head. Design the MyCircularQueue class with: MyCircularQueue(k) to initialize with capacity k; enQueue(value) to insert and return true on success; deQueue() to remove from front and return true on success; Front() and Rear() to peek at the front/back (return -1 if empty); isEmpty() and isFull() status checks. Do not use a built-in queue.

Example 1:

Input

["MyCircularQueue", "enQueue", "enQueue", "enQueue", "enQueue", "Rear", "isFull", "deQueue", "enQueue", "Rear"]

[[3], [1], [2], [3], [4], [], [], [], [4], []]

Output

[null, true, true, true, false, 3, true, true, true, 4]

Example 2:

Explanation

MyCircularQueue myCircularQueue = new MyCircularQueue(3);

myCircularQueue.enQueue(1); // return True

myCircularQueue.enQueue(2); // return True

myCircularQueue.enQueue(3); // return True

myCircularQueue.enQueue(4); // return False

myCircularQueue.Rear(); // return 3

myCircularQueue.isFull(); // return True

myCircularQueue.deQueue(); // return True

myCircularQueue.enQueue(4); // return True

myCircularQueue.Rear(); // return 4

Code

class MyCircularQueue:

    def __init__(self, k: int):
        

    def enQueue(self, value: int) -> bool:
        

    def deQueue(self) -> bool:
        

    def Front(self) -> int:
        

    def Rear(self) -> int:
        

    def isEmpty(self) -> bool:
        

    def isFull(self) -> bool:
        


# 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()

class MyCircularQueue:

    def __init__(self, k: int):
        

    def enQueue(self, value: int) -> bool:
        

    def deQueue(self) -> bool:
        

    def Front(self) -> int:
        

    def Rear(self) -> int:
        

    def isEmpty(self) -> bool:
        

    def isFull(self) -> bool:
        


# 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()