#!/usr/bin/perl

use strict;

# Eingabe
my @array = (1..9);

my %res;
warn time;
oneless(@array);
warn time;

# Formatierung der Ausgabe
# Key als Array umschreiben
my @res;
while(my($k) = each %res) {
    push @res, [split /,/, $k];
}
# Ergebnisarray schoener sortieren
@res = sort {
    my $r = @$a <=> @$b;
    if ($r == 0) {
        join(",", @$a) cmp join(",", @$b);
    } else {
        $r;
    }
} @res;
require Data::Dumper;
print Data::Dumper->new([\@res],['res'])->Indent(0)->Dump, "\n";

sub oneless {
    my @array = @_;
    $res{ join",",@array } = 1;
    return if !@array;
    for my $i (0 .. $#array) {
        oneless(map { $array[$_] } 0 .. $i-1, $i+1 .. $#array);
    }
}