Given a paragraph of text, write a program to find the first shortest sub-segment that contains each of the given k words at least once. A segment is said to be shorter than other if it contains less number of words.
Ignore characters other than [a-z][A-Z] in the text. Comparison between the strings should be case-insensitive. If no sub-segment is found then the program should output “NO SUBSEGMENT FOUND”. --
