SplPriorityQueue
At this time, the documentation sais "Note: Multiple elements with the same priority will get dequeued in no particular order."
If you need elements of equal priority to maintain insertion order, you can use something like:
<?php
class StablePriorityQueue extends SplPriorityQueue {
protected $serial = PHP_INT_MAX;
public function insert($value, $priority) {
parent::insert($value, array($priority, $this->serial--));
}
}
?>
SplPriorityQueue::compare
(PHP 5 >= 5.3.0)
SplPriorityQueue::compare — Compare priorities in order to place elements correctly in the heap while sifting up.
Description
Compare priority1 with priority2 .
Parameters
- priority1
-
The priority of the first node being compared.
- priority2
-
The priority of the second node being compared.
Return Values
Result of the comparison, positive integer if priority1 is greater than priority2 , 0 if they are equal, negative integer otherwise.
Note: Multiple elements with the same priority will get dequeued in no particular order.
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User Contributed NotesSplPriorityQueue::compare
Anonymous
11-Oct-2009 01:51
11-Oct-2009 01:51