Implement Stack using Queues

Implement a last-in-first-out (LIFO) stack using only two queues. The implemented stack should support all the functions of a normal stack (`push`, `top`, `pop`, and `empty`). Implement the `MyStack` class: - `void push(int x)` Pushes element x to the top of the stack. - `int pop()` Removes the element on the top of the stack and returns it. - `int top()` Returns the element on the top of the stack. - `boolean empty()` Returns `true` if the stack is empty, `false` otherwise. Notes: - You must use **only** standard operations of a queue, which means that only `push to back`, `peek/pop from front`, `size` and `is empty` operations are valid. - Depending on your language, the queue may not be supported natively. You may simulate a queue using a list or deque (double-ended queue) as long as you use only a queue's standard operations.   **Example 1:** **Input** ["MyStack", "push", "push", "top", "pop", "empty"] [[], [1], [2], [], [], []] **Output** [null, null, null, 2, 2, false] **Explanation** MyStack myStack = new MyStack(); myStack.push(1); myStack.push(2); myStack.top(); // return 2 myStack.pop(); // return 2 myStack.empty(); // return False ```   **Constraints:** - `1 <= x <= 9` - At most `100` calls will be made to `push`, `pop`, `top`, and `empty`. - All the calls to `pop` and `top` are valid.   **Follow-up:** Can you implement the stack using only one queue?