递归反转一个栈

递归反转一个栈，要求空间复杂度为1，不许重新申请一个同样的栈

算法思想：汉诺塔的思想 function ReserveStack(&$stack){
if(empty($stack)) return;
$top = array_pop($stack);
ReserveStack($stack);
if(empty($stack)){
array_push($stack,$top);
return;
}
$top2 = array_pop($stack);
ReserveStack($stack);
array_push($stack,$top);
ReserveStack($stack);
array_push($stack,$top2);
}

$test = array(3,1,5,6,7,9,10,2);
ReserveStack($test);
print_r($test);