Package g0601_0700.s0641_design_circular_deque

Class MyCircularDeque

  • public class MyCircularDeque
extends Object
    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.

    • Constructor Detail

      • MyCircularDeque

        public MyCircularDeque​(int k)

    • Method Detail

      • insertFront

        public boolean insertFront​(int value)

      • insertLast

        public boolean insertLast​(int value)

      • deleteFront

        public boolean deleteFront()

      • deleteLast

        public boolean deleteLast()

      • getFront

        public int getFront()

      • getRear

        public int getRear()

      • isEmpty

        public boolean isEmpty()

      • isFull

        public boolean isFull()