Chapter 10, Problem 4E

Write a program that will record the purchases made at a store. For each purchase, read from the keyboard an item's name, its price, and the number bought. Compute the cost of the purchase (number bought times price), and write all this data to a text file. Also, display this information and the current total cost on the screen. After all items have been entered, write the total cost to both the screen and the file. Since we want to remember all purchases made, you should append new data to the end of the file.