Data commit

Task/Goldbachs-comet/Perl/goldbachs-comet.pl

@@ -0,0 +1,36 @@
+use strict;
+use warnings;
+use feature 'say';
+
+use List::Util 'max';
+use GD::Graph::bars;
+use ntheory 'is_prime';
+
+sub table { my $t = shift() * (my $c = 1 + max map {length} @_); ( sprintf( ('%'.$c.'s')x@_, @_) ) =~ s/.{1,$t}\K/\n/gr }
+
+sub G {
+    my($n) = @_;
+    scalar grep { is_prime($_) and is_prime($n - $_) } 2 .. $n/2;
+}
+
+my @y;
+push @y, G(2*$_ + 4) for my @x = 0..1999;
+
+say $_ for table 10, @y;
+printf "G $_: %d", G($_) for 1e6;
+
+my @data = ( \@x, \@y);
+my $graph = GD::Graph::bars->new(1200, 400);
+$graph->set(
+    title          => q/Goldbach's Comet/,
+    y_max_value    => 170,
+    x_tick_number  => 10,
+    r_margin       => 10,
+    dclrs          => [ 'blue' ],
+) or die $graph->error;
+my $gd = $graph->plot(\@data) or die $graph->error;
+
+open my $fh, '>', 'goldbachs-comet.png';
+binmode $fh;
+print $fh $gd->png();
+close $fh;