PHP解决约瑟夫环的问题

//准备好41个人
$people = array();
for($i=0;$i<=40;$i++) {
$people[] = $i+1;
}

/**
* @param $people  准备好的数组
* @param $step    每到第几个人,会把他杀掉
* @param int $jsq 计数器,不用传
*/
function killPeople($people, $step, $jsq = 0) {
//开始杀人
$cnt = count($people);
for($i=0;$i<$cnt;$i++) {
$jsq++;
if($jsq == $step) {
echo $people[$i] . "号被杀掉了<br/>";
unset($people[$i]);
$jsq = 0;
}
}
if(count($people) == ($step - 1)) {
die('<hr/>'.implode(',', $people) . '被留下了');
}
killPeople(array_values($people), $step, $jsq);
}
killPeople($people, 3);