singly linked list stack 基于单链表的栈

public class LinkedStack<E> implements Stack<E>{
    SinglyLinkedList<E> data;
    public LinkedStack() { data = new SinglyLinkedList<>();}
    @Override
    public int size() { return data.size(); }
    @Override
    public boolean isEmpty() { return data.isEmpty(); }
    @Override
    public void push(E e) { data.addFirst(e); }
    @Override
    public E pop() { return data.removeFirst(); }
    @Override
    public E top() { return data.first(); }
}