sub pascal {
  my ($rows) = @_;
  print "1\n";
  for (my $outer = 1; $outer < $rows; $outer++) {
    my $inner = $outer;
    print "1";
    for ($i = 1; $i < $inner; $i++) {
      my $denominator = factorial($i)*(factorial($inner-$i)); 
      my $pascalnum = factorial($inner)/$denominator if ($denominator != 0);
      print " $pascalnum" if ($outer > 1);
    }
    print " 1\n";
  }
}

##</code><code>##

sub ton_pascal
{
    my $rows = shift;
    my $last_row = [ ];
    my $this_row = [ 1 ];
    
    last unless ($rows > 0);
    print "1\n";
    for (my $i = 1; $i < $rows; ++$i) {
        $last_row = $this_row;
        $this_row = [ 1 ];
        for (my $j = 1; $j < $i; $j++) {
            push(@$this_row, $last_row->[$j - 1] + $last_row->[$j]);
        }
        push(@$this_row, 1);
        print join(' ', @$this_row) . "\n";
    }    
}