Question #5 -- Longest Words

Write a program that processes a data file by identifying and displaying the set of words with the most characters in that file. There should be no limit on the size of the file or the number of words that qualify.

What is a Word?

A word is a sequence of alphabet (a-z or A-Z) characters. non-alphabetic characters such as spaces, tabs, ' , -, 9, etc. are considered to be separators and not part of a word.

What qualifies a word as longest? No other word in the file has more characters.

Example content of an input file:

                 	This is JUST
                        a TesT. I Hope All Is Well!
                        good luck with this 1.
Expected Output for that file: Note that largest words are in lower case and each is only displayed once regardless of the number of times it occurs in the file. The order is not important.
                    Longest Words
                        good
                        this
                        just
                        luck
                        well
                        hope
                        with
                        test