CS 131 PROGRAMMING ASSIGNMENT 3   

Convert assignment 2 so that it processes 5 transactions and sends the results 
to a file. Your program will prompt the user for the cost of each item and calculate 
the change as in last week's program. Use a for loop.

OUTPUT: A file "change.dat" with a table that has headings for the cost of the 
item and the number of quarters, dimes, and pennies to be received in change. 
For example, with input data 72, 39, 10, 25, and 20, the output would be

           COST                      CHANGE
        (in cents)           Quarters Dimes  Pennies

            72                   1      0       3
            39                   2      1       1
            10                   3      1       5
            25                   3      0       0
            20                   3      0       5 

If the user enters enters a number less than 0 or greater than 100, print a line 
in the file indicating invalid data.  For example, with input data 72, -3, and 10, 
25, and 20 the output would be

           COST                     CHANGE
        (in cents)           Quarters Dimes  Pennies

            72                   1      0       3
            -3               *****invalid data****
            10                   3      1       5
            25                   3      0       0
            20                   3      0       5 

Suggestion: first write your program assuming all data is valid, then add the
capability to handle invalid data.  Use a boolean variable validData.

* Propose and implement a way to find the total of all valid purchases so that, for 
example, the output in case 1 would be

           COST                     CHANGE
        (in cents)           Quarters Dimes  Pennies

            72                   1      0       3
            39                   2      1       1
            10                   3      1       5
            25                   3      0       0
            20                   3      0       5 

        The sum of all purchases is $1.66