import java.util.ArrayList;

public class QM<W> implements QueueInterface<W>, QMerge<W> {

    ArrayList<W> cq = new ArrayList<>();

    @Override
    public int size() {
        return cq.size();
    }

    @Override
    public boolean isEmpty() {
        return cq.size()==0;
    }

    @Override
    public W first() {
        if (isEmpty())
            return null;
        return cq.get(0);
    }

    @Override
    public void enqueue(W e) {
        cq.add(e);
    }

    @Override
    public W dequeue() {
        if (isEmpty())
            return null;
        W tmp = cq.get(0);
        cq.remove(0);
        return tmp;
    }

    public String toString() {
        return cq.toString();
    }

    public static void main(String[] args) {
        QM<Integer> qq = new QM<>();
        qq.enqueue(-3);
        qq.enqueue(7);
        qq.enqueue(14);
        qq.enqueue(18);
        QM<Integer> qr = new QM<>();
        for (int i=0; i<10; i++)
            qr.enqueue(i);
        System.out.println(qq);
        System.out.println(qr);
        QueueInterface<Integer> resu = qq.queueMerge(qq,qr);
        System.out.println(resu);
    }

    @Override
    public QueueInterface<W> queueMerge(QueueInterface<W> q1, QueueInterface<W> q2) {
        QM<W> merged = new QM<>();
        while (!q1.isEmpty() || !q2.isEmpty()) {
            if (q2.isEmpty()) {
                merged.enqueue(q1.dequeue());
            } else if (q1.isEmpty()) {
                merged.enqueue(q2.dequeue());
            } else {
                if (((Comparable)q2.first()).compareTo(((Comparable)q1.first())) < 0) {
                    merged.enqueue(q2.dequeue());
                } else {
                    merged.enqueue(q1.dequeue());
                }
            }
        }
        return merged;
    }

}