SplMinHeap::compare
quick implementation of SPL Priority Queue:
<?php
class PQtest extends SplPriorityQueue
{
public function compare($priority1, $priority2)
{
if ($priority1 === $priority2) return 0;
return $priority1 < $priority2 ? -1 : 1;
}
}
$objPQ = new PQtest();
$objPQ->insert('A',3);
$objPQ->insert('B',6);
$objPQ->insert('C',1);
$objPQ->insert('D',2);
echo "COUNT->".$objPQ->count()."<BR>";
//mode of extraction
$objPQ->setExtractFlags(PQtest::EXTR_BOTH);
//Go to TOP
$objPQ->top();
while($objPQ->valid()){
print_r($objPQ->current());
echo "<BR>";
$objPQ->next();
}
?>
output:
COUNT->4
Array ( [data] => B [priority] => 6 )
Array ( [data] => A [priority] => 3 )
Array ( [data] => D [priority] => 2 )
Array ( [data] => C [priority] => 1 )
The SplPriorityQueue class
(PHP 5 >= 5.3.0)
Introduction
The SplPriorityQueue class provides the main functionalities of an prioritized queue, implemented using a max heap.
Class synopsis
/* Methods */
}Table of Contents
- SplPriorityQueue::compare — Compare priorities in order to place elements correctly in the heap while sifting up.
- SplPriorityQueue::__construct — Constructs a new empty queue
- SplPriorityQueue::count — Counts the number of elements in the queue.
- SplPriorityQueue::current — Return current node pointed by the iterator
- SplPriorityQueue::extract — Extracts a node from top of the heap and sift up.
- SplPriorityQueue::insert — Inserts an element in the queue by sifting it up.
- SplPriorityQueue::isEmpty — Checks whether the queue is empty.
- SplPriorityQueue::key — Return current node index
- SplPriorityQueue::next — Move to the next node
- SplPriorityQueue::recoverFromCorruption — Recover from the corrupted state and allow further actions on the queue.
- SplPriorityQueue::rewind — Rewind iterator back to the start (no-op)
- SplPriorityQueue::setExtractFlags — Sets the mode of extraction
- SplPriorityQueue::top — Peeks at the node from the top of the queue
- SplPriorityQueue::valid — Check whether the queue contains more nodes
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User Contributed Notes
SplPriorityQueue - [2 notes]
rajatn at rediff dot co dot in ¶
2 years ago