PHP 7 Data Structures and Algorithms

Implement a priority queue using SplPriorityQueue

PHP already has a built-in support for implementing a priority queue using SPL. We can use the SplPriorityQueue class to implement our priority queues. Here is the sample previous example using a linked list, but this time we are choosing SPL:

class MyPQ extends SplPriorityQueue {     public function compare($priority1, $priority2) {     return $priority1 <=> $priority2;     }}$agents = new MyPQ();$agents->insert("Fred", 1); $agents->insert("John", 2);$agents->insert("Keith", 3);$agents->insert("Adiyan", 4);$agents->insert("Mikhael", 2);//mode of extraction$agents->setExtractFlags(MyPQ::EXTR_BOTH); //Go to TOP$agents->top();while ($agents->valid()) {    $current = $agents->current(); echo $current['data'] ...