use strict;
#generate all posibilites of a DNA sequence
my @Bases = qw(A C G T);
my $SequenceMinLenght = 1;
my $SequenceMaxLength = 3;
my @SequenceLenghts = ($SequenceMinLenght...$SequenceMaxLength);
#print "@SequenceLenghts\n";
my $SequenceListLength = $#SequenceLenghts;
$SequenceListLength ++;
print "Number of Sequence lenghts to permute is $SequenceListLength\n";
my @allSequence = ();
my $sequence;
my $currLenght;
my @Ordered_Combinations_input = ();
foreach $currLenght (@SequenceLenghts){
	@Ordered_Combinations_input = ();
	@Ordered_Combinations_input = ($currLenght, @Bases);
	@allSequence = (@allSequence, (&Ordered_Combinations (@Ordered_Combinations_input)));	
}
#Prints sequences to screen
# - Too many entries after lenght of sequence is grater than 4.  
my $i=0;
foreach my $finalsequence (@allSequence){
	$i ++;
	if ($i == 4){
		print "$finalsequence\n";
		$i= 0;
	}
	else{
		print "$finalsequence\t";
	}
}
#Completely blow the GOLF chalange by using a sub name almost as long as the sub
#See http://www.perlmonks.com/index.pl?node_id=75261 for details 
sub Ordered_Combinations {my$n=shift;--$n?map{my$d=$_;map$d.$_,Ordered_Combinations($n,@_)}@_:@_};