#!/usr/bin/perl
use warnings;
use strict;

open (DATA, "dictionary") || die "Error opening the input file\n"; 
print "Reading mapping file\n";
print "----------------------------\n";
    
open (INFILE, "corpus.txt") || die "Error opening the input file\n"; 
print "Reading input file\n";
print "----------------------------\n";

my %dict;
while ( <DATA> ) {

    my ( $key, $val ) = /^(\d+)\s+(\w+)/;
    $val = lc($val);
    $dict{ $val } = $key;
    }

my $cc = join '', keys %dict;
my ( $min ) = my ( $max ) = map length, keys %dict;

for ( map length, keys %dict ) {
    $min = $_ if $min > $_;
    $max = $_ if $max < $_;
    }

my $pattern = qr/\b([$cc]{$min,$max})\b/;


while (my $line = <INFILE>) {
my $old_string = $line;


( my $new_string = $old_string ) =~ s/$pattern/ exists $dict{ $1 } ? $dict{ $1 } : $1 /eg;
print "$new_string";

}
close (INFILE);
close (DATA);

##</code><code>##

__DATA__
1 cross
2 reference
3 cross-reference

__INFILE__
cross-reference

__OUTPUT__
3-2

__EXPECTED-OUTPUT__
3