Any type of suggestion is appreciated.

You've described the task very clearly; what you've omitted to describe is which part of the problem you are having a problem with?

• Reading the files?
• Parsing their content?
• Accumulating the ranges?
• Deciding what goes in which file?
• Writing the output?

The following code first organizes the intervals into %changes where the beginning and end of each interval are the main keys, i.e. you can walk the keys and see all the points where the situation changes (hence the name).

The second group of loops walks the "changes", and records how many intervals are currently "active", in %current . If the number of current intervals of the same id is the same as the number of input files, the point is stored in %intervals as the starting point; and similarly for the end points.

#!/usr/bin/perl
use warnings;
use strict;
use feature qw{ say };

my %changes;
for my $file (@ARGV) {
    open my $in, '<', $file or die "$file: $!";
    while (<$in>) {
        chomp;
        my ($id, $intervals_string) = split /: /;
        my @intervals = map [ split /-/ ], split /, /, $intervals_stri
+ng;

        for my $interval (@intervals) {
            my ($from, $to) = @$interval;
            $changes{$from}{$id}{$file} = 'start';
            $changes{$to}{$id}{$file}   = 'end';
        }
    }
}

my %current;
my %intervals;
for my $point (sort { $a <=> $b } keys %changes) {
    for my $id (keys %{ $changes{$point} }) {
        for my $file (keys %{ $changes{$point}{$id} }) {

            if ('start' eq $changes{$point}{$id}{$file}) {
                $current{$id}{$file} = 1;
                push @{ $intervals{$id} }, [$point] if @ARGV == keys %
+{ $current{$id} };

            } else {
                $intervals{$id}[-1][1] = $point if @ARGV == keys %{ $c
+urrent{$id} };
                delete $current{$id}{$file};
                delete $current{$id} if ! keys %{ $current{$id} };
            }
        }
    }
}

for my $id (keys %intervals) {
    say "$id: ", join ', ', map "$_->[0]-$_->[1]", @{ $intervals{$id} 
+};
}
[download]

($q=q:Sq=~/;[c](.)(.)/;chr(-||-|5+lengthSq)`"S|oS2"`map{chr |+ord
}map{substrSq`S_+|`|}3E|-|`7**2-3:)=~y+S|`+$1,++print+eval$q,q,a,
[download]

Any type of suggestion is appreciated.

start simple and build up , for example

my( $left, $right ) = extractRange( '68485121: 20-42' );
sub extractRange {
    my( $line ) = @_;
    ...
}
[download]

See perlintro, Files and I/O, Parentheses for capturing and http://perldoc.perl.org/perlrequick.html#Extracting-matches, open, split...

It's important in homework to show your work. Let's see what you have so far.

Perhaps more importantly, you need to work out how to solve this. How would you do this with pencil and paper? That would be where I would start.

Hi abhikalrt53,

Monk utpalmtbi had a question similar to yours a little while ago: finding intermediate range values from two file columns. I suggest you read the discussion there to get you started, especially the module recommendations.

Hope this helps,
-- Hauke D