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.
add a note
User Contributed Notes
SplPriorityQueue::compare - [1 notes]
Anonymous ¶
3 years ago