sub DefaultHashValue {
    my %h = @_;
    my %r = reverse %h;
    my @k = sort values %h;
    return $r{ $k[0] }
}

##</code><code>##

sub sort_keys {
    my %h = @_;
    my @s = sort { $h{$a} cmp $h{$b} } keys %h;
    return $s[0]
}

##</code><code>##

sub min {
    my %h = @_;
    my $min = (keys %h)[0];
    $h{$_} lt $h{$min} and $min = $_ for keys %h;
    return $min
}

##</code><code>##

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

use Test::More;
use Benchmark qw{ cmpthese };


sub orig {
    my %h = @_;
    my %r = reverse %h;
    return $r{ (sort values %h)[0] }
}


sub Sort {
    my %h = @_;
    return (sort { $h{$a} cmp $h{$b} } keys %h)[0]
}


sub min {
    my %h = @_;
    my $min = (keys %h)[0];
    $h{$_} lt $h{$min} and $min = $_ for keys %h;
    return $min
}


# TEST
for my $t (
           { a => 'A', b => 'B', c => 'C' },
           { abc => 'ABC', def => 'ABC' , xyz => 'XYZ' },
           { 1 .. 1_000},
           { map int rand 100, 1 .. 1_000 },
          ) {
    my $o = orig(%$t);
    is  Sort(%$t), $o, "onleline-$o";
    is  min(%$t),  $o, "min-$o";
}


done_testing();


# BENCHMARK
for my $size (10, 100, 1_000, 5E4, 1E6) {

    my %h = map int rand 100, 1 .. $size;

    cmpthese(0,
             { orig => sub { orig(%h) },
               sort => sub { Sort(%h) },
               min  => sub { min(%h)  },
             });
}