Implementing Queue with Two Stacks

Your task is to implement a queue using two stacks. You are provided with ‘Q’ queries and need to handle them, where each query falls under one of these two operations:

1. Enqueue an element ‘X’ to the end of the queue.
2. Dequeue an element from the front of the queue.

Functionality:

• For enqueue, return true after the element is enqueued.
• For dequeue, return -1 if the queue is empty, otherwise return the dequeued element.

Example:

Input:

5
1 10
1 20
2
1 30
2

Output:

true
true
10
true
20

Explanation:

The given queries perform the following operations:

• Enqueue 10: Returns true
• Enqueue 20: Returns true
• Dequeue: Returns 10 (dequeued)
• Enqueue 30: Returns true
• Dequeue: Returns 20 (dequeued)

Constraints:

• 1 <= Q <= 10^5
• 1 <= P <= 2
• 1 <= X <= 10^5 (for enqueue operation)
• Time limit: 1 sec