#!/usr/bin/perl

use Benchmark qw(timethese cmpthese);

print "SMALL HASH SIZES:-\n\n";

run_timings(
    150_000,             # Iterations
    10, 100, 1000        # Hash Sizes
);

print "LARGE HASH SIZES:-\n\n";

run_timings(
    50,                  # Iterations
    10_000, 50_000       # Hash Sizes
);

print "HUGE HASH SIZES:-\n\n";

run_timings(
    5,                   # Iterations
    100_000, 1_000_000   # Hash Sizes
);

exit;

sub run_timings {
    my $iterations = shift;
    my @hash_sizes = @_;
    
    for my $n (@hash_sizes) {
    
        my %hashName = map { $_ => $_ } 1 .. $n;
    
        print "------------------------------------------\n";
        print "Hash size: ", scalar(keys(%hashName)), "\n";
        print "Max Value: ", (sort { $b <=> $a } values %hashName)[0], "\n";

        print "Timings:\n\n";
        my $r = timethese($iterations, {
            'new' => sub {
                my ($max) = sort { $b <=> $a } values %hashName;
            },
            'nosort' => sub {
                my $max, $val;
                while ((undef, $val) = each %hashName) {
                    $max ||= $val;
                    $max = $val if $val >= $max;
                }
            },
        });

        print "\nComparasion:\n\n";
        cmpthese($r);

        print "\n\n";
    }
}

__END__

Timing results follow:-