PHP は 24 点ゲームを計算します

求: 三五、一一構成の数学表式の結果=24, 結果:(5-1/5)*5=24

set_time_limit(0);
$values = array (1, 5, 5, 5);
$result = 24;

$list = array();

echo "

";
 makeValue($values);
 print_r($list);
 
 関数 makeValue($values, $set=array())
 {
 $words = array("+", "-", "*", "/");
 if(sizeof($values)==1 )
 {
 $set[] = array_shift($values);
 return makeSpecial($set);
 }
 foreach($values as $key=>$value)
 {
 $tmpValues = $values;
 unset ($tmpValues[$key]);
 foreach($words as $word)
 {
 makeValue($tmpValues, array_merge($set, array($value, $word)));
 }
 }
 } 
 
 function makeSpecial($set)
 {
 $size = sizeof($set);
 if($size<=3 || !in_array("/", $set) && !in_array("*", $set) )
 {
 return makeResult($set);
 }
 for($len=3; $len<$size-1; $len+=2)
 {
 for($start=0; $start<$size -1; $start+=2)
 {
 if(!($set[$start-1]=="*" || $set[$start-1]=="/" || $set[$start+ $len]=="*" || $set[$start+$len]=="/"))
 続行;
 $subSet = array_slice($set, $start, $len);
 if(!in_array "+", $subSet) && !in_array("-", $subSet))
 続行;
 $tmpSet = $set;
 array_splice($tmpSet, $start, $len-1);
 $tmpSet[$start ] = "(".implode("", $subSet).")";
 makeSpecial($tmpSet); 
 }
 }
 } 

 function makeResult($set)
 {
 global $result, $list;
 $str = implode("", $set);
 @eval("$num=$str;" );
 if($num==$result && !in_array($str, $list))
 $list[] = $str;
 } 
?>