JAVA ДЛЯ ПОТОКОВ ИВБО / ПР-11 / StackOnQueue

import java.util.LinkedList;
import java.util.Queue;

public class StackOnQueue {
    private Queue<Integer> queueA;
    private Queue<Integer> queueB;

    public StackOnQueue() {
        queueA = new LinkedList<>();
        queueB = new LinkedList<>();
    }
    public void push(int x) {
        queueB.offer(x);
        while (!queueA.isEmpty()) {
            queueB.offer(queueA.poll());
        }
        Queue<Integer> temp = queueA;
        queueA = queueB;
        queueB = temp;
    }
    public int pop(){
        return queueA.poll();
    }
    public int top(){
        return queueA.peek();
    }
    public boolean empty(){
        return queueA.isEmpty();
    }
    public String toString() {
        return queueA.toString();
    }
}