Quiz

Build a LIFO (last-in-first-out) stack using only two queues as the underlying data structure. The stack must support four operations: push, pop, top, and empty.

Implement the MyStack class:

- void push(int x) Adds element x to the top of the stack.

- int pop() Removes and returns the top element.

- int top() Returns the top element without removing it.

- boolean empty() Returns true when the stack is empty, false otherwise.

Constraints:

- Only standard queue operations are permitted: enqueue to back, peek/dequeue from front, size check, and empty check.

- If your language lacks a native queue, a list or deque used strictly as a queue is acceptable.