return a boolean true if all rotations of strng are included in arr (C returns 1

contain_all_rots.php

 <?php
 
 /**
  * return a boolean true if all rotations of strng are included in arr (C returns 1)
  * 
  * @param string $s 
  * @param array $arr
  * @return boolean
  * @author Phan Vu Hoang <vu-hoang.phan@ekino.com>
  */
function containAllRots($s, $arr)
{
    // all rotations
    $s2 = array();
    for ($i = 0; $i < strlen($s); $i++) {
        $s2[] = substr($s, $i) . substr($s, 0, $i);
    }
    
    return (array_intersect($s2, $arr) === $s2) ? true : false;
} 

function containAllRots_alt($s, $arr) {
    foreach (str_split($s) as $char) {
        $s = substr($s, 1) . $char;
        if(!in_array($s, $arr)) return false;
    }

    return true;
}