In the concordance problem of Segment 20.18, if a word occurs more than once in a single line, the number of that line appears more than once in the concordance. Revise the method read File given in...

In the concordance problem of Segment 20.18, if a word occurs more than once in a single line, the number of that line appears more than once in the concordance. Revise the method read File given in Segment 20.20 so that the line numbers associated with a given word are distinct.