codility-lesson2-OddOccurrencesInArray.php

<?php
// you can write to stdout for debugging purposes, e.g.
// print "this is a debug message\n";

function solution($A) {

    $a_count_values = array_count_values($A);
    $values = array_keys($a_count_values, 1);
    if (is_array($values))
        return $values[0];
    return $values;

}