#!/usr/bin/env perl
use strict;
use warnings;
use Math::Prime::Util qw/nth_prime prime_precalc/;
use Benchmark qw/:all :hireswallclock/;
use Data::Dumper;
my $count = shift || -5;
#prime_precalc(1000000000);
srand(29);
my @darray;
push @darray, [gendigits($_,int(5400/($_*$_*$_)))] for 2 .. 13;
my $sum;
foreach my $digits (3 .. 12) {
my @digarray = @{$darray[$digits-2]};
my $numitems = scalar @digarray;
my $timing = cmpthese(
$count,
{ "$digits" => sub { $sum += nth_prime($_) for @digarray }, },
'none',
);
my $secondsper = $timing->[1]->[1];
if ($timing->[0]->[1] eq 'Rate') {
$secondsper =~ s/\/s$//;
$secondsper = 1.0 / $secondsper;
}
$secondsper /= $numitems;
my $timestr = (1.0 / $secondsper) . "/s per number";
printf "%4d %2d-digit numbers: %s\n", $numitems, $digits, $timestr;
}
sub gendigits {
my $digits = shift;
die "Digits must be > 0" unless $digits > 0;
my $num = shift;
my $base = ($digits == 1) ? 0 : int(10 ** ($digits-1));
my $max = int(10 ** $digits);
$max = ~0 if $max > ~0;
my @nums = map { $base+int(rand($max-$base)) } (1 .. $num);
return @nums;
}