数据结构 栈和队列及递归算法

用Java语言：
使用3个队列，分别保留手机上最近10个，未接来电、已接来电、已拨电话

public class Main {
    public static void main(String[] args) {
        Main main = new Main();

        Op op = new Op();
        Scanner sc = new Scanner(System.in);
        int type;
        while((type=sc.nextInt())!=Op.OP_FINISH){
            String mobile = "";
            if (type < 4) {
                mobile = sc.next();
            }

            op.operator(type,mobile);
        }
    }

    static class Op{
        Memory tel;
        Memory notAccept;
        Memory accept ;
        public static final int OP_TEL = 1;
        public static final int OP_REFUSE = 2;
        public static final int OP_ACCEPT = 3;
        public static final int OP_TEL_PRINT = 4;
        public static final int OP_REFUSE_PRINT = 5;
        public static final int OP_ACCEPT_PRINT = 6;
        public static final int OP_FINISH = 7;
        public Op(){
            tel = new Memory();
            notAccept = new Memory();
            accept = new Memory();
        }

        public void operator(int type,String mobile){
            switch (type){
                case OP_TEL:
                    addTel(mobile);
                    break;
                case OP_REFUSE:
                    addNotAccept(mobile);
                    break;
                case OP_ACCEPT:
                    addAccept(mobile);
                    break;
                case OP_TEL_PRINT:
                    System.out.println(getTelList());
                    break;
                case OP_REFUSE_PRINT:
                    System.out.println(getNotAcceptList());
                    break;
                case OP_ACCEPT_PRINT:
                    System.out.println(getAcceptList());
                    break;

            }
        }

        public void addTel(String mobile){
            tel.add(mobile);
        }

        public Queue<String> getTelList(){
            return tel.getList();
        }

        public void addNotAccept(String mobile){
            notAccept.add(mobile);
        }

        public Queue<String> getNotAcceptList(){
            return notAccept.getList();
        }

        public void addAccept(String mobile){
            accept.add(mobile);
        }

        public Queue<String> getAcceptList(){
            return accept.getList();
        }
    }



    static class Memory{
        Queue<String> list = null;//拨出

        public Memory(){
            list = new LinkedList<>();

        }

        public void add(String mobile){
            list.offer(mobile);
            if(list.size()>10)
                list.poll();
        }

        public Queue<String> getList(){
            return list;
        }



    }
}

public static void main(String[] args) {
            //add()和remove()方法在失败的时候会抛出异常(不推荐)
            Queue<String> wjld = new LinkedList<String>();
            //添加元素
            wjld.offer("a");
            wjld.offer("b");
            wjld.offer("c");
            wjld.offer("d");
            wjld.offer("e");
            wjld.offer("a");
            wjld.offer("b");
            wjld.offer("c");
            wjld.offer("d");
            wjld.offer("e");
            Queue<String> yjld = new LinkedList<String>();
            //添加元素
            yjld.offer("a");
            yjld.offer("b");
            yjld.offer("c");
            yjld.offer("d");
            yjld.offer("e");
            yjld.offer("a");
            yjld.offer("b");
            yjld.offer("c");
            yjld.offer("d");
            yjld.offer("e");
            Queue<String> ybdh = new LinkedList<String>();
            //添加元素
            ybdh.offer("a");
            ybdh.offer("b");
            ybdh.offer("c");
            ybdh.offer("d");
            ybdh.offer("e");
            ybdh.offer("a");
            ybdh.offer("b");
            ybdh.offer("c");
            ybdh.offer("d");
            ybdh.offer("e");

        }