function calcShortestPaths(vertex $start, &$adjLists)
{
// define an empty queue
$q = new PriorityQueue();
// push the starting vertex into the queue
$q->insert($start, 0);
$q->rewind();
// mark the distance to it 0
$start->distance = 0;
// the path to the starting vertex
$start->path = array($start->key);
while ($q->valid()) {
$vertex = $q->extract();
$vertex->visited = 1;
$list = $adjLists[$vertex->key];
while ($list->valid()) {
$item = $list->current();
if (!$item['vertex']->visited) {
if ($item['vertex']->distance > $vertex->distance + $item['distance']) {
$item['vertex']->distance = $vertex->distance + $item['distance'];
$item['vertex']->parent = $vertex;
}
$item['vertex']->path = array_merge($vertex->path, array($item['vertex']->key));
$q->insert($item["vertex"], $item["vertex"]->distance);
}
$list->next();
}
$q->recoverFromCorruption();
$q->rewind();
}
}
function calcDistances($start)
{
// define an empty queue
$q = new PriorityQueue();
// push the starting vertex into the queue
$q->insert($start, 0);
$q->rewind();
// mark the distance to it 0
$start->distance = 0;
while ($q->valid()) {
$t = $q->extract();
$t->visited = 1;
foreach ($t->getRelations() as $key => $relation) {
foreach ($relation as $object) {
if (!$object->visited) {
if ($object->distance > $t->distance + 1) {
$object->distance = $t->distance + 1;
$object->parent = $t;
}
$q->insert($object, $object->distance);
}
}
}
$q->recoverFromCorruption();
$q->rewind();
}
}
