> For the complete documentation index, see [llms.txt](https://luj.gitbook.io/code/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://luj.gitbook.io/code/data-structure/queue/design-circular-deque.md).

# Design Circular Deque

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

Your implementation should support following operations:

* `MyCircularDeque(k)`: Constructor, set the size of the deque to be k.
* `insertFront()`: Adds an item at the front of Deque. Return true if the operation is successful.
* `insertLast()`: Adds an item at the rear of Deque. Return true if the operation is successful.
* `deleteFront()`: Deletes an item from the front of Deque. Return true if the operation is successful.
* `deleteLast()`: Deletes an item from the rear of Deque. Return true if the operation is successful.
* `getFront()`: Gets the front item from the Deque. If the deque is empty, return -1.
* `getRear()`: Gets the last item from Deque. If the deque is empty, return -1.
* `isEmpty()`: Checks whether Deque is empty or not. 
* `isFull()`: Checks whether Deque is full or not.

## **Example**

```
MyCircularDeque circularDeque = new MycircularDeque(3); // set the size to be 3
circularDeque.insertLast(1);            // return true
circularDeque.insertLast(2);            // return true
circularDeque.insertFront(3);            // return true
circularDeque.insertFront(4);            // return false, the queue is full
circularDeque.getRear();              // return 2
circularDeque.isFull();                // return true
circularDeque.deleteLast();            // return true
circularDeque.insertFront(4);            // return true
circularDeque.getFront();            // return 4
```

## Note

类似[Design Circular Queue](/code/data-structure/queue/design-circular-queue.md)