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You want to be able to access the largest element in a stack.
You've already implemented this Stackclass:
# Initializes an empty stack.
@items = 
# Pushes a new item onto the stack.
@items << item
# Removes and returns the last item.
# If the stack is empty, returns nil. (It would also be
# reasonable to throw an exception.)
# Returns the last item without removing it.
Use yourStackclass to implement a newclassMaxStack with a methodget_max that returns the largest element in the stack.get_max should not remove the item.
Your stacks will contain only integers.
What if we push several items in increasing numeric order (like 1, 2, 3, 4...), so that there is a new max after each push? What if we then pop each of these items off, so that there is a new max after each pop? Your algorithm shouldn't pay a steep cost in these edge cases.
You should be able to get a runtime of for push, pop, and get_max.
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