CSci 3102  Winter 1994  Extension
Lab 3
Due: 16 Feb.


A plastics recovery firm purchases truckloads of plastics of different
types mixed together and runs it through an automatic sorting and
reprocessing center. It pays its suppliers based on the amount of
different plastics that are extracted and the amount of time that it
takes to process the plastic into usable material of a given type.

For each truckload of plastic that is processed, an operator enters
the time that the processing run started, the time that the processing
run ended, the number of pounds of plastic in the truckload, and the
number of pounds of each of two types of plastic that was extracted
(which may sum to less than the truckload weight because of waste).
The plant operates around the clock and the times are entered in 24
hour time.  For example, 11:45 PM would be entered as 2345 while 3:15
AM would be entered as 0315.  A processing run may start at 2345 and
end at 0315. Assume that a run is always less than 24 hours.

The supplier is paid $0.06 per pound for type 1 plastic and $0.04 per
pound for type 2 plastic minus a $45 per hour processing charge.  If
the processing charge is larger than the amount due the supplier the
supplier gets nothing (instead of having to pay for the processing).

Write a program that will read in the information from the operator
and print out an invoice indicating the amount to be paid. The invoice
should indicate the number of pounds in the truckload, the number of
pounds, rate and amount paid for each type of plastic, the charge for
processing, and the amount to be paid to the supplier.

Be sure to include error checking of relevant input, such as times are
valid and the sum of recovered plastics is not greater than the
truckload weight. Use good programming style (including using
constants as appropriate).  You must use some meaningful subprograms
in this assignments.

PROCEDURES AND FUNCTIONS MAY NOT ACCESS GLOBAL VARIABLES.