function checkPrerequisites($cid, $selectedCourse)
{
$prerequisites = getPrerequisitesStringByCid($cid);
//echo $prerequisites;
$array = transPreToCNF($prerequisites);
//print_r($array);
// $error=array();
$count = 0;
$error = "";
if ($prerequisites != null) {
for ($i = 0; $i < count($array); $i++) {
//1.将array[$i]中的or 解析出来，放在新数组中
$orArray = divOrStringIntoArray($array[$i]);
//2.将这个数组放入profile里面进行查询，返回T or F
//print_r($orArray);
//3. 返回F就给$error赋值，否则继续
if (!isInStu_offering($orArray)) {
if (!isInSelectedCourse($orArray, $selectedCourse)) {
$error .= echoOrString($orArray) . "\n";
$count++;
}
}
}
}
if ($count != 0) {
return $error;
} else {
return "true";
}
}
function checkRestriction($cid, $selectedCourse)
{
$restriction = getRestrictionStringByCid($cid);
$array = transRestrictionToCNF($restriction);
$error = array();
$count = 0;
$error[$count] = null;
if ($restriction != null) {
for ($i = 0; $i < count($array); $i++) {
$orArray = divOrStringIntoArray($array[$i]);
if (isInStu_offering($orArray)) {
$error[$count] = $array[$i];
$count++;
} else {
if (isInSelectedCourse($orArray, $selectedCourse)) {
$error[$count] = $array[$i];
$count++;
}
}
}
}
if ($count != 0) {
return false;
} else {
return true;
}
}
