Introduction - If you have any usage issues, please Google them yourself
Program read from a document file crossin.txt. The document consists of several lines, each line contains a series of words. The input document where all occurrences of the word and its line number in the output to a file crossout.txt. There are a number of output lines, each line is a word appears in the document. Output specifications as follows: word: line1, line2, ..., lineN