Silly Japanese homework bruteforce tool

bruteforce.pl

use feature 'say';

my $NUMCARDS = $ARGV[0]*2;
die "Usage: perl bruteforce.pl [NUMBER OF CARDS]\n" unless $ARGV[0];

say "num cards: $NUMCARDS";

my @init = split'','.'x$NUMCARDS;

&iterate_desc($NUMCARDS/2,@init);
#&iterate_asc(1,@init);

sub iterate_desc($@){
  my $number = shift;	
	for (my$i=0;$i<$NUMCARDS-$number-1;$i++){
		
		my @var = @_;
		
		if($var[$i] eq '.' && $var[$i+$number+1] eq '.'){
			
			# OK to put to this position
			$var[$i] = $number;
			$var[$i+$number+1] = $number;
			
			# Uncomment to display permutations
			#say join ' ',@var;
			
			if($number>1){
				iterate_desc($number-1,@var);
			} else {
				say "Solution: ",join('',@var);
			}	
		}
	}
}

# sub iterate_asc($@){
# 	my $number = shift;	
# 	for (my$i=0;$i<$NUMCARDS-$number-1;$i++){
# 		my @var = @_;
# 		if($var[$i] eq '.' && $var[$i+$number+1] eq '.'){
# 			# OK to put to this position
# 			$var[$i] = $number;
# 			$var[$i+$number+1] = $number;
# 			# Uncomment to display permutations
# 			#say join ' ',@var; 
# 			if($number<$NUMCARDS/2){
# 				iterate_asc($number+1,@var);
# 			} else {
# 				say "Solution: ",join('',@var);
# 			}	
# 		}	
# 	}
# }