DouKaku?

#!/usr/local/bin/perl
use strict;
use warnings;
use Memoize;

sub young {
    my $n = shift;
    die 'young($n); # where $n is an integer' unless $n;
    return [1] if $n == 1;
    my @result = ( [$n] );
    for my $k ( reverse 1 .. $n - 1 ) {
        push @result,
          map { [ $k, @$_ ] } grep { $k >= $_->[0] } young( $n - $k );
    }
    @result;
}

memoize 'young';

sub print_young{
    my $n = shift;
    local $\ = "\n";
    for my $a (young($n)){
        print '#' x $_ for @$a;
        print "=" x $n;
    }
}

my ($n, $quiet) = @ARGV;
$quiet ? young($n) : print_young($n);
__END__
% perl young.pl 5
#####
=====
####
#
=====
###
##
=====
###
#
#
=====
##
##
#
=====
##
#
#
#
=====
#
#
#
#
#
=====
% time perl young.pl 50 1
9.390u 0.783s 0:10.29 98.8%     0+0k 0+1io 0pf+0w
% time sh -c 'perl young.pl 50 | grep = | wc'
  204226  204226 10415526
10.903u 0.894s 0:11.82 99.7%    0+0k 0+3io 0pf+0w