4.6 使用链表实现栈

 1 public class LinkedListStack<E> implements Stack<E> {
 2 
 3     private LinkedList<E> list;
 4 
 5     public LinkedListStack(){
 6         list = new LinkedList<>();
 7     }
 8 
 9     @Override
10     public int getSize(){
11         return list.getSize();
12     }
13 
14     @Override
15     public boolean isEmpty(){
16         return list.isEmpty();
17     }
18 
19     @Override
20     public void push(E e){
21         list.addFirst(e);
22     }
23 
24     @Override
25     public E pop(){
26         return list.removeFirst();
27     }
28 
29     @Override
30     public E peek(){
31         return list.getFirst();
32     }
33 
34     @Override
35     public String toString(){
36         StringBuilder res = new StringBuilder();
37         res.append("Stack: top ");
38         res.append(list);
39         return res.toString();
40     }
41 
42     public static void main(String[] args) {
43 
44         LinkedListStack<Integer> stack = new LinkedListStack<>();
45 
46         for(int i = 0 ; i < 5 ; i ++){
47             stack.push(i);
48             System.out.println(stack);
49         }
50 
51         stack.pop();
52         System.out.println(stack);
53     }
54 }