Package g0601_0700.s0641_design_circular_deque

Class MyCircularDeque

  • All Implemented Interfaces:
    
public final class MyCircularDeque

    641 - Design Circular Deque.

    Medium

    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.