use strict;
use warnings;
use Data::Dump qw/pp dd/;
use List::Util qw(min max);
use constant { name=>0, num=>1 };

my @AoA = 
(
    ["nick","99"],
    ["john","88"],
    ["peter","77"],
    ["thomas","99"]
);

my $max_num   = max map { $_->[num] } @AoA;
my @max_names =
  map  { $_->[name] }
  grep { $_->[num] == $max_num }
  @AoA;

pp @max_names;

##</code><code>##

my @max_names =
  map { $_->[num] == $max_num ? $_->[name] : () }
  @AoA;