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

my ($stellen,@elemente)=@ARGV;
die "Aufruf:\n   $0 stellen element_a [element_b [element_c [ ...]]]\n" if(@elemente==0 || $stellen!~/^\d+$/);

sub permutation($@)
{
  my ($st,@arr) = @_;
  my @ret=();
  my @cnt=map{$_=0}(1..$st);
  ende:while(1)
  {
   push(@ret,join('',map{$_=$arr[$_]}@{[@cnt]}));
   for my $i (0..$st-1)
   {
    if($cnt[$i]<@arr-1)
    {
     $cnt[$i]++;
     last;
    }
    else
    {
     $cnt[$i]=0;
     last(ende) unless( exists($cnt[$i+1]) );
    }
   }
  }
  return @ret;
}

print "Elemente: ".join('; ', @elemente)."\n";
print "Stellen: $stellen\n";
print "Variantionen:\n";
print join("\n",&permutation($stellen,@elemente)),"\n";