stack push - ANS-inserts an item on the top of the stack
stack pop - ANS-removes and returns the item at the top of the stack
Stack peek - ANS-return the next item in LIFO ordering
Stack isEmpty - ANS-Returns true if stack has no items
Queue enqueue - ANS-adds item to end
queue dequeue - ANS-removes and returns the next item in fifo ordering
queue peek - ANS-return without removing the next item in fifo ordering
deque - ANS-A ______ is a "doubled-ended queue"
addfirst - ANS-add item to front of deque
addlast - ANS-add item to end fo deque
remove first - ANS-remove first item
remove last - ANS-remove last item