Implement the following and hand it in on Wednesday for extra credit
on the first Exam. You will be given a full class period to apply
towards this goal. Also don't forget that mentors will be available on
Tuesday in the lab to assist.

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The following is problem #4.2 from Introduction to Programming with
C++ - Comprehensive Version by Y. Daniel Liang.

4.2: (Counting positive and negative numbers and computing the average
of numbers) Write a program that reads an unspecified number of
integers, determines how many positive and negative values have been
read, and computes the total and average of the input values (not
counting zeros). Your program ends with the input 0. Display the
average as a floating-point number. (For example, if you entered 1, 2,
and 0, the average should be 1.5.)