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();
}
}