#!/usr/local/bin/perl

print "Enter number of rows...\n";

chomp (my $rows = <>);

print "You entered $rows for rows\n";

pascal($rows);

sub pascal {
  my ($rows) = @_;
  print "1\n";
  for (my $outer = 1; $outer <= $rows; $outer++) {
    my $inner = $outer;
    print "1" unless ($outer == 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" unless ($outer == 1);
  }
}

sub factorial {
  my ($factorial) = @_;
  my $answer = $factorial;
  while ($factorial) {
    $factorial--;
    $answer *= $factorial unless ($factorial == 0);
  }
  return $answer;
}