向 Deque 新增元素
Deque deque = new LinkedList();
//Adding element at tail
deque.add("Item1");
//Adding element at head
deque.addFirst("Item2");
//Adding element at tail
deque.addLast("Item3");
Deque deque = new LinkedList();
//Adding element at tail
deque.add("Item1");
//Adding element at head
deque.addFirst("Item2");
//Adding element at tail
deque.addLast("Item3");