算法--列（java實現）

public class Queue {
    //創建兩個節點，一個保存數據，一個指向節點
    public Node head;
    public Node current;

    //添加節點
    public void add(int data) {
        if(head == null) {
            head = new Node(data);
            current = head;
        } else {
        //current.next指向新建節點
        //current指向current.next
        //也就是current指向新建節點
            current.next = new Node(data);
            current = current.next;
        }
    }

    public Node pop() {
        if(head == null) {
            return null;
        }

        Node node = head;
        head = head.next;

        return node;
    }

    class Node{
        int data;
        Node next;

        public Node(int data) {
            this.data = data;
        }
    }


    public static void main(String[] args) {
        Queue queue = new Queue();
        for(int i=0; i<5; i++) {
            queue.add(i);
        }
        System.out.println(queue.pop().data);
        System.out.println(queue.pop().data);
        System.out.println(queue.pop().data);
        System.out.println(queue.pop().data);
        System.out.println(queue.pop().data);

    }
}