- Difficulty: Medium
- Tags: LeetCode, Medium, Design, Queue, Array, Linked List, leetcode-641, O(1)
Problem
Design your implementation of the circular double-ended queue (deque).
Implement the MyCircularDeque
class:
MyCircularDeque(int k)
Initializes the deque with a maximum size ofk
.boolean insertFront()
Adds an item at the front of Deque. Returnstrue
if the operation is successful, orfalse
otherwise.boolean insertLast()
Adds an item at the rear of Deque. Returnstrue
if the operation is successful, orfalse
otherwise.boolean deleteFront()
Deletes an item from the front of Deque. Returnstrue
if the operation is successful, orfalse
otherwise.boolean deleteLast()
Deletes an item from the rear of Deque. Returnstrue
if the operation is successful, orfalse
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()
Returnstrue
if the deque is empty, orfalse
otherwise.boolean isFull()
Returnstrue
if the deque is full, orfalse
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 toinsertFront
,insertLast
,deleteFront
,deleteLast
,getFront
,getRear
,isEmpty
,isFull
.