DLLDeque

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Team JDK: Judy Liu, David Frid, Karina Ionkina

Rationale for method selections:

The doubly-linked queue should have "enqueue", "dequeue" and "peek" capabilities on either end. The methods we chose allow for adding and removing elements in both directions.

Methods

1. public void addFirst(T x)

• Adds the element to the front of the deque

2. public T removeFirst()

• Removes the element at the front of the deque and returns the removed element and throws error if empty

3. public T peekFirst()

• Returns the element at the front of the deque

4. public void addLast(T x)

• Adds the element to the end of the deque

5. public T removeLast()

• Removes the element at the end of the deque and returns the removed element and throws error if empty

6. public T peekLast()

• Returns the element at the end of the deque

7. public boolean isEmpty()

• Returns true if the first element is null

8. public int size()

• Returns number of elements present

Rationale for Doubly-linked Node-based Architecture

Our team choose doubly-linked Node-based architecture for Deque because Deque is a double ended queue. The instance variables nextNode and prevNode and their methods from the doubly-linked nodes would be useful in adding, removing, and peeking from the front or end of the queue.