find the kth least frequent element in an array in php

main.php
function kthLeastFrequent($arr, $k) {
  // count frequency of each element in the array
  $count = array();
  foreach ($arr as $elem) {
    if (array_key_exists($elem, $count)) {
      $count[$elem]++;
    } else {
      $count[$elem] = 1;
    }
  }
  
  // sort the counts in ascending order
  asort($count);
  
  // get the kth least frequent element
  $kth = null;
  $i = 0;
  foreach ($count as $elem => $freq) {
    $i++;
    if ($i == $k) {
      $kth = $elem;
      break;
    }
  }
  
  return $kth;
}

// example usage
$arr = array(1, 2, 3, 2, 2, 3, 4, 4, 5);
$k = 3;
$kthLeastFrequentElem = kthLeastFrequent($arr, $k);
echo "The ".$k."th least frequent element in the array is ".$kthLeastFrequentElem; // output: The 3th least frequent element in the array is 5
772 chars
34 lines