Implement stack using a queue

Question

deveffort · Accepted Answer

I think the question is to implement a stack using a queue DS. 
For every push(), enqueu() in the queue. Then dequeu() every element and enqueue() the same immediately until we reach the element which was recently enqueued. 
This way we maintain the queue in the form expected by the stack (LIFO)

Sigiloso · Answer

deveffort, i guess you will have to maintain 2 queues. After the first dequeue, your queue will contain items that are needed for stack retrieval(LIFO). But any more items you want to add to this queue will mess it up unless  you maintain another queue. 
So retrievals are always from one queue and additions area always on a different queue.

Anonymous · Answer

You need two stacks.  You push to stack A, and pop from stack B.  When B is empty, you reverse A onto B.

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