#!/usr/bin/perl
use warnings;
use strict;
use feature qw{ say };
use Scalar::Util qw{ dualvar };

warn "start\n";
my $tstart1 = time;
our (%by_word, @data);
while (<>) {
    chomp;
    my ($k, $v) = split /\t/, $_;
    $by_word{$k} += $v;
}

my $tend1 = time;
warn "get properties: ", $tend1 - $tstart1, " secs\n";

my $tstart2 = time;
while (my ($k, $v) = each %by_word) {
    push @data, dualvar($v, $k);
}

# output array of dualvars; sorted by number desc, string asc
say "$_\t".(0+$_) for sort { $b <=> $a } sort { $a cmp $b } @data;

my $tend2 = time;
warn "sort + output: ", $tend2 - $tstart2, " secs\n";
warn "total: ", $tend2 - $tstart1, " secs\n";