use strict;
use warnings;
use Data::Dumper;

my @masterArray = (
                  ["this", "that", 12563, "something", "else"],
                  ["this", "that", 10, "something", "else"],
                  ["this", "that", 1, "something", "else"],
                  ["this", "that", 125638, "something", "else"],
                  ["this", "that", 300000, "something", "else"],
                   );

my @top3 = sort {$b->[2] <=> $a->[2]} @masterArray[0..2];
my $min_top = $top3[2][2];

for my $sub_aref (@masterArray [3..$#masterArray]) {
	next if $sub_aref <= $min_top;
	@top3 =  (sort {$b->[2] <=> $a->[2]} @top3, $sub_aref)[0..2];
	$min_top = $top3[2][2];
}
print Dumper @top3;

##</code><code>##

$ perl  subdiscard.pl
$VAR1 = [
          'this',
          'that',
          300000,
          'something',
          'else'
        ];
$VAR2 = [
          'this',
          'that',
          125638,
          'something',
          'else'
        ];
$VAR3 = [
          'this',
          'that',
          12563,
          'something',
          'else'
        ];

##</code><code>##

use strict;
use warnings;
use Data::Dumper;
my $nb_elements = shift;
chomp $nb_elements ;

my @masterArray;

push @masterArray, ["", "", int rand (1e7), ""] for 1..$nb_elements;

# print Dumper \@masterArray;

my @top3 = sort {$b->[2] <=> $a->[2]} @masterArray[0..2];
my $min_top = $top3[2][2];
$nb_elements--;
for my $sub_aref (@masterArray [3..$nb_elements]) {
	next if $sub_aref->[2] <= $min_top;
	@top3 =  (sort {$b->[2] <=> $a->[2]} @top3, $sub_aref)[0..2];
	$min_top = $top3[2][2];
}
print Dumper \@top3;

##</code><code>##

$ time perl  subdiscard2.pl 1000000
$VAR1 = [
          [
            '',
            '',
            9999996,
            ''
          ],
          [
            '',
            '',
            9999993,
            ''
          ],
          [
            '',
            '',
            9999990,
            ''
          ]
        ];

real    0m2.497s
user    0m2.386s
sys     0m0.108s

##</code><code>##

$ time perl  subdiscard3.pl 1000000
$VAR1 = [
          [
            '',
            '',
            9999980,
            ''
          ],
          [
            '',
            '',
            9999955,
            ''
          ],
          [
            '',
            '',
            9999944,
            ''
          ]
        ];

real    0m7.605s
user    0m7.518s
sys     0m0.093s