#! perl -slw
use strict;
use Time::HiRes qw[ time ];
use List::MoreUtils qw[ uniq ];

sub idx{
    my $idx = chr(0) x 4;
    vec( $idx, $_, 1 ) = 1 for map ord()-ord('a'), uniq sort split'', $_[ 0 ];
    $idx;
}

my %idx;

open DICT, '<', 'junk.words' or die $!;
while( <DICT> ) {
    chomp;
    push @{ $idx{ idx( $_ ) } }, $_;
}
my @keys = keys %idx;
print scalar @keys;

while( <> ) {
    my $start = time;
    my @matches;
    my $n = 0;
    chomp;
    ( my $pat = $_ ) =~ tr[a-z][]cd;
    $pat = idx( $pat );
    for my $idx ( grep+(($_ & $pat) eq $pat), @keys ) {
        for my $poss ( @{ $idx{ $idx } } ) {
            $poss =~ $_ and $matches[ $n++ ] = $poss;
        }
    }
    printf "Found $n matches in  %.2f seconds; Display? ", time() - $start;
    if( <> =~ /y/i ) {
        print for @matches;
    }
}