Standard telephone keypads contain the digits 0 through 9. Digits 2 through 9 each have three or four letters associated with them, as follows:
Each 7 digit phone number corresponds to many separate 7 letter words. One of the possible letter combination for the number 639-2277 is "NEWCARS".
Write a program that, given a seven digit number, writes to a file every possible combination corresponding to that number. Avoid phone numbers with digits 0 or 1.
Q: How many such combinations are there?
The program has a GUI that allows the user to enter the phone number. The GUI also allows browsing by using the file chooser, to find the output file and allows for a text area to display the contents of the file.
A sample file is provided