代碼樣例

public class LinkedStack<T> {
    private static class Node<U>{
        U item;
        Node<U> next;
        public Node() {
            this.item=null;
            this.next=null;
        }

        public Node(U item, Node<U> next) {
            this.item = item;
            this.next = next;
        }
        boolean end(){return item==null && next==null;}
    }
    private Node<T> top = new Node<T>();
    public void push(T item){
        top = new Node<T>(item,top);
    }
    public T pop(){
        T result = top.item;
        if (!top.end()) top = top.next;
        return result;
    }

    public static void main(String[] args) {

    }