#!/usr/bin/perl

use strict;

my $n = 10;

for my $i (0 .. $n) {
	
	for my $j (0 .. $i) {
		my $coefficient = nCr($i, $j);
		if ($coefficient % 2) {
			print '#';
		} else {
			print ' ';
		}
	}
	
	print "\n";
}

# returns n!/r!(n-r)!
sub nCr
{
    my $n=shift;
    my $r=shift;

    return int nFactorial($n) / int nFactorial($r) * int nFactorial($n-$r);
}

# like the name says, n!
sub nFactorial
{
    my $n=shift;
    my $product = 1;

    while($n>0)
    {
        $product *= $n--;
    }

    return  $product;
}