0641. Design Circular Deque

https://leetcode.com/problems/design-circular-deque

Description

Design your implementation of the circular double-ended queue (deque).

Implement the MyCircularDeque class:

• MyCircularDeque(int k) Initializes the deque with a maximum size of k.

• boolean insertFront() Adds an item at the front of Deque. Returns true if the operation is successful, or false otherwise.

• boolean insertLast() Adds an item at the rear of Deque. Returns true if the operation is successful, or false otherwise.

• boolean deleteFront() Deletes an item from the front of Deque. Returns true if the operation is successful, or false otherwise.

• boolean deleteLast() Deletes an item from the rear of Deque. Returns true if the operation is successful, or false otherwise.

• int getFront() Returns the front item from the Deque. Returns -1 if the deque is empty.

• int getRear() Returns the last item from Deque. Returns -1 if the deque is empty.

• boolean isEmpty() Returns true if the deque is empty, or false otherwise.

• boolean isFull() Returns true if the deque is full, or false otherwise.

Example 1:

**Input**
["MyCircularDeque", "insertLast", "insertLast", "insertFront", "insertFront", "getRear", "isFull", "deleteLast", "insertFront", "getFront"]
[[3], [1], [2], [3], [4], [], [], [], [4], []]
**Output**
[null, true, true, true, false, 2, true, true, true, 4]
**Explanation**
MyCircularDeque myCircularDeque = new MyCircularDeque(3);
myCircularDeque.insertLast(1);  // return True
myCircularDeque.insertLast(2);  // return True
myCircularDeque.insertFront(3); // return True
myCircularDeque.insertFront(4); // return False, the queue is full.
myCircularDeque.getRear();      // return 2
myCircularDeque.isFull();       // return True
myCircularDeque.deleteLast();   // return True
myCircularDeque.insertFront(4); // return True
myCircularDeque.getFront();     // return 4

Constraints:

• 1 <= k <= 1000

• 0 <= value <= 1000

• At most 2000 calls will be made to insertFront, insertLast, deleteFront, deleteLast, getFront, getRear, isEmpty, isFull.

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