1997 Woburn Computer Programming Challenge

Searching and sorting are part of the theory and practice of computer science. For example, binary search provides a good example of an easy-to-understand algorithm with sublinear complexity. Quicksort is an efficient $\mathcal{O}(n\log n)$ [average case] comparison sort. KWIC-indexing is an indexing method that permits efficient "human search" of, for example, a list of titles.

Given a list of titles and a list of "words to ignore," you are to write a program that generates a KWIC (Key Word In Context) index of the titles. In a KWIC-index, a title is listed once for each keyword that occurs in the title. The KWIC-index is alphabetized by keyword. Any word that is not one of the "words to ignore" is a potential keyword. For example, if the words to ignore are the, of, and, as, and a and the list of titles is

• descent of man
• the ascent of man
• the old man and the sea
• a portrait of the artist as a young man

A KWIC-index of these titles might be given by

Input Specification

The first few lines of the input are a series of "words to ignore." Each is on a line by itself and is no more than $20$ characters in length.
The list of words to ignore is terminated by the string :: on a line by itself.
The next lines are the titles to be incorporated into the KWIC-index. Each contains no more than $15$ words, all in lowercase, separated by single spaces. No word is longer than $20$ characters, and no title is longer than $250$ characters.

There will be no more than $50$ words to ignore, no more than $100$ titles, and no more than $200$ keywords in the titles. No characters other than a to z and white spaces will appear in the input.

Output Specification

The output should be a KWIC-index of the titles, with each title appearing once for each keyword in the title, and with the KWIC-index alphabetized by keyword. If a word appears more than once in a title, each instance is a potential keyword. The keyword should appear in all uppercase letters; all other words should be lowercase letters. Titles in the KWIC-index with the same keyword should appear in the same order as they appeared in the input file. In the case where multiple instances of a word are keywords in the same title, the keywords should be capitalized in left-to-right order. The titles in the KWIC-index should NOT be justified by keyword, and must be listed left-justified.

Sample Input

is
the
of
and
as
a
but
::
descent of man
the ascent of man
the old man and the sea
a portrait of the artist as a young man
a man is a man but bubblesort is a dog

Sample Output

a portrait of the ARTIST as a young man
the ASCENT of man
a man is a man but BUBBLESORT is a dog
DESCENT of man
a man is a man but bubblesort is a DOG
descent of MAN
the ascent of MAN
the old MAN and the sea
a portrait of the artist as a young MAN
a MAN is a man but bubblesort is a dog
a man is a MAN but bubblesort is a dog
the OLD man and the sea
a PORTRAIT of the artist as a young man
the old man and the SEA
a portrait of the artist as a YOUNG man