use strict;
use warnings;


# Create a hash of arrays of data about individual users
my %user_data;
foreach my $file (
        "Carlo_Arnold_2.232_Final.txt",
        "Sohaib_Ahmad_2.225_Final.txt"
) {
        open(my $fh, '<', $file) or die "$file: $!";
        foreach (<$fh>) {
                chomp;
                foreach ( map { [ split(/:/, $_) ] } <$fh> ) {
                        push(@{$user_data{$_->[0]}}, $_->[1]);
                }

        }
        close($fh);
}


# An input LOG file which holds information about different users.
my $file_name = "QoEWeb_DB_Log.txt";
open(my $sw, '<', $file_name) or die "$file_name: $!";


#Will write the result into an OUTPUT file.
open(my $file, '>', 'output.txt') or die "output.txt: $!";

foreach (
        sort { $a->[8] <=> $b->[8] } map { chomp; [ split /:/ ] } <$sw>
) {
        my ($field1, $field2, $key1, $field5) = @$_[2,4,8,6];

        foreach (@{$user_data{$key1}}) {
                #Printing the desired result from both batch of input files.
                print  $file "$field1:$field2:$key1:$field5:$_";
        }
}
close $file or die "output.txt: $!";
close $sw or die "$file_name: $!";