Implement a queue using stack(s). Asked in the Technical Round 1 stage.
Use two stacks to process operations in first-in, first-out order. Implement queue_operations(operations), where each operation is one of ['push', value], ['pop'], ['peek'], or ['empty']. Return the results of pop, peek, and empty operations in order. Inputs will not call pop or peek when the queue is empty.
def queue_operations(operations):