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

my @words = split /\s+/, <<WORDS;
a alien all allows always an and are as best but can certainly command
confession context counting dictionary does each even fact find for found from
have here hope i if immediate importance intuitively is just letter letters like
list low make mimic monks my need never obvious occur of one only option pattern
per perl physical plainer pure question quite regex regexp search tablet that
the these thing think this those to tokens up use using which with words you
WORDS
my %normLu;

push @{$normLu{normWord ($_)}}, $_ for @words;

my $match = buildRegex ('adeilln');
my @matches = map {@{$normLu{$_}}} grep {/^$match$/} keys %normLu;

print "@matches\n";


sub normWord {
    return join '', sort split '', $_[0];
}

sub buildRegex {
    my ($word) = @_;
    my %freq;

    ++$freq{$_} for split '', $word;
    return join '', map {"$_\{0,$freq{$_}\}"} sort keys %freq;
}

##</code><code>##

alien all and an a i