Binary Search

<?php

function find($array, $x) {
    $mid = floor(count($array)/2);
    if ($array[$mid] === $x) { // integer found
        return true;
    } elseif (count($array) === 1) { // integer not found when only one element left
        return false;
    } elseif ($array[$mid] > $x) { // recursive function with lower array
        return find(array_slice($array, 0, count($array)/2), $x);
    } else  { // recursive function with upper array
        return find(array_slice($array, count($array)/2), $x);
    }
}

// driver code
$found = find(array(1,2,3,4,5,6),2);
if ($found) {
    echo 'Found';
} else {
    echo 'Not Found';
}

?>