Perform Queries

Amazon ships millions of packages every day. A large percentage of them are fulfilled by Amazon, so it is important to minimize shipping costs. It has been found that moving a group of 3 packages to the shipping facility together is most efficient. The shipping process needs to be optimized at a new warehouse. There are the following types of queries or requests:

• INSERT package id: insert package id in the queue of packages to be shipped
• SHIP -: ship the group of 3 items that were in the queue earliest i.e. they are returned in the order they entered

Perform q queries and return a list of lists, one for every SHIP - type query. The lists are either; 3 package ID strings in the order they were queued. Or, if there are not enough packages in the queue to fulfill the query, the result is I"N/A"J.

Note:

• Initially, the queue is empty.
• The list of packages shipped per group should be in the order they were queued. The function performQueries take

  List<List<>>

  of type String as a parameter which contains each query where - 🦆

--> list.get(i).get(0) = INSERT | SHIP

--> list.get(i).get(1) = shipmentID | -

Returns List>: a list of lists, one for every SHIP - type query