deQueue - Notes By ShariqSP

Deque Interface in Java

The Deque interface in Java represents a double-ended queue, which allows insertion and removal of elements from both ends. It extends the Queue interface and provides additional methods for insertion and removal at both ends.

Methods:

• addFirst(E element): Inserts the specified element at the front of the deque.
• addLast(E element): Inserts the specified element at the end of the deque.
• removeFirst(): Removes and returns the first element of the deque.
• removeLast(): Removes and returns the last element of the deque.
• getFirst(): Retrieves, but does not remove, the first element of the deque.
• getLast(): Retrieves, but does not remove, the last element of the deque.
• isEmpty(): Returns true if the deque contains no elements.
• size(): Returns the number of elements in the deque.
• clear(): Removes all elements from the deque.

Implementation Classes:

The Deque interface has several implementation classes in Java:

• ArrayDeque: Resizable-array implementation of the Deque interface.
• LinkedList: Doubly linked list implementation of the Deque interface.