一个强悍的算24点游戏的PHP程序

"; makeValue($values); print_r($list);function 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]=="/")) 				continue; 			$subSet = array_slice($set, $start, $len); 			if(!in_array("+", $subSet) && !in_array("-", $subSet)) 				continue; 			$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; }?>

程序运行结果为：

Array(    [0] => (5-1/5)*5    [1] => 5*(5-1/5))