[LeetCode]Implement Stack using Queues

class MyStack {
    // Push element x onto stack.
    Queue<Integer> queue = new LinkedList<Integer>();
    public void push(int x) {
        Queue<Integer> q = new LinkedList<Integer>();
        q.offer(x);
        while (!queue.isEmpty()) {
            q.offer(queue.poll());
        }
        queue = q;
    }

    // Removes the element on top of the stack.
    public void pop() {
        queue.poll();
    }

    // Get the top element.
    public int top() {
        return queue.peek();
    }

    // Return whether the stack is empty.
    public boolean empty() {
        return queue.isEmpty();
    }
}