Chapter 7, Problem 7.21E

(Sales Summary) Use a two-dimensional array to solve the following problem. A company
has four salespeople (l to 4) who sell five different products (l to 5). Once a day, each salesperson
passes in a slip for each different type of product sold. Each slip contains the following:

1. The salesperson number
2. The product number
3. The total dollar value of that product sold that day

Thus, each salesperson passes in between 0 and 5 sales slips per day. Assume that the information from all of the slips for last month is available. Write a program that will read all this information for last month's sales (one salesperson's data at a time) and summarize the total sales by salesperson by product. All totals should be stored in the two-dimensional array sales. After processing all the information for last month, print the results in tabular format with each of the columns represent- ing a particular salesperson and each of the rows representing a particular product. Cross total each row to get the total sales of each product for last month; cross total each column to get the total sales by salesperson for last month. Your tabular printout should include these cross totals to the right of the totaled rows and to the bottom of the totaled columns.