function pickCourse($course, $leftToTake, $coursesPicked, $lab, $solutions)
{
global $courses_array;
$coursesArr = $courses_array;
//end conditions
if ($course == "" && empty($leftToTake) && !empty($coursesPicked)) {
$timeTable = new TimeTable($coursesPicked);
$timeTable->generateTimeTable();
//make sure there isn't a conflict in the timetable, then add solution to list
if ($timeTable->hasConflict() === FALSE) {
if (is_null($solutions)) {
$solutions = array();
}
array_push($solutions, $timeTable->courseList);
}
return $solutions;
} else {
//build array of options for the current course/lab
$newArr = array();
foreach ($coursesArr as $precise) {
$courseName = $precise['course_name'];
$courseSection = $precise['course_section'];
if ($course == $courseName) {
preg_match('/\\d/', $courseSection, $match);
$checkIsLab = $match;
if (!$checkIsLab && $lab == "") {
array_push($newArr, $precise);
} else {
if ($checkIsLab && $lab !== "") {
array_push($newArr, $precise);
}
}
}
}
//if the class section has a lab section with the same Letter, than that lab letter needs to be selected
//figure out if lab section with the same letter as course section exists
$hasLetterSection = FALSE;
if ($lab != "") {
$courseSect = $lab;
foreach ($newArr as $checkLabSect) {
if (substr($checkLabSect['course_section'], 0, 1) == $lab) {
$hasLetterSection = TRUE;
break;
}
}
}
$courseReached = FALSE;
if ($course != "" && sizeof($newArr) == 0) {
$picked = $coursesPicked;
$left = $leftToTake;
$key = array_search($course, $left);
array_splice($left, $key, 1);
$empty = empty($left);
if ($empty && !empty($picked)) {
//last course, so finish
$solutions = pickCourse("", array(), $picked, "", $solutions);
if (sizeof($solutions) > 1) {
return $solutions;
//break;
}
} else {
if (!$empty) {
//not last course, keep looking for solutions
$solutions = pickCourse($left[0], $left, $picked, "", $solutions);
if (sizeof($solutions) > 1) {
return $solutions;
//break;
}
}
}
}
//iterate over list, selecting a course, then doing it again for the next
foreach ($newArr as $courses) {
$courseName = $courses['course_name'];
$section = $courses['course_section'];
//shouldn't need anymore
preg_match('/\\d/', $section, $match);
$isLab = $match;
if ($lab && !$isLab) {
continue;
}
//shouldn't need this if statment anymore
if ($courseName == $course) {
$courseReached = TRUE;
$picked = $coursesPicked;
$left = $leftToTake;
array_push($picked, $courseName . "-" . $section);
if (!$lab) {
//next course chosen should be the lab for the current course selected
$solutions = pickCourse($course, $leftToTake, $picked, substr($section, 0, 1), $solutions);
if (sizeof($solutions) > 1) {
return $solutions;
//break;
}
continue;
} else {
if ($isLab) {
if (!($hasLetterSection && $lab == substr($section, 0, 1) || !$hasLetterSection)) {
//ex: SYSC 4504 A is selected, SYSC 4504 B1 should not be a lab selected (wrong section)
//therefore continue if this is the case
continue;
}
}
//remove the current course from the list of courses to take (don't want to select it again)
$key = array_search($course, $left);
array_splice($left, $key, 1);
if (empty($left)) {
//this was the last course, therefore see if the solution works
$solutions = pickCourse("", array(), $picked, "", $solutions);
if (sizeof($solutions) > 1) {
return $solutions;
//break;
}
continue;
} else {
//try next course
$solutions = pickCourse($left[0], $left, $picked, "", $solutions);
if (sizeof($solutions) > 1) {
return $solutions;
//break;
}
continue;
}
}
//might not need anymore
} else {
if ($courseReached || $course == "") {
break;
}
}
}
// nothing left to do... end
return $solutions;
}
}
