Midterm Coding Quiz - Time limit 40 min

How to submit

• Fork this repository, implement your code on your fork and make sure to push it when you're done.
• Add gade.as@northeastern.edu, devarapalli.n@northeastern.edu as collaborators to your fork.
• Do not make your fork public and do not create a pull request.
• Your last commit time will be recorded as your submission time.

Problem Statement

Design your implementation of the circular queue using 2 pointers (front & rear). 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.

Implement the MyCircularQueue class:

• MyCircularQueue(k) Initializes the object with the size of the queue to be k.
• int Front() Gets the front item from the queue. If the queue is empty, return -1.
• int Rear() Gets the last item from the queue. If the queue is empty, return -1.
• boolean enQueue(int value) Inserts an element into the circular queue. Return true if the operation is successful.
• boolean deQueue() Deletes an element from the circular queue. Return true if the operation is successful.
• boolean isEmpty() Checks whether the circular queue is empty or not.
• boolean isFull() Checks whether the circular queue is full or not.

You must solve the problem without using the built-in queue data structure.

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]

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

Constraints:

• 1 <= k <= 1000
• 0 <= value <= 1000
• At most 3000 calls will be made to enQueue, deQueue, Front, Rear, isEmpty, and isFull.