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\textbf{CS 181b} \\ Advanced Topics in Algorithms \\ Spring 2002 \\
Problem Set 2a \\ Due Thursday, January 31 in class
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\item \textbf{[20 Points]  ACN Programming Competition!}
You are competing in the International ACN (Association of
Computer Nerds) Programming Competition.  In one of the programming
problems, you need to implement a queue.  Unfortunately, you are pressed
for time.  Fortunately, you already have good working code for a stack. 
You may assume that the stack is implemented efficiently and supports
operations PUSH, POP, and SIZE (which returns the number of items on the
stack) in time $O(1)$.  Show how 2 stacks can be instantiated to
implement a queue. Moreover, show that the amortized running time for
ENQUEUE and DEQUEUE are $O(1)$ using this 2-stack implementation.


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