Оптимизация / кэширование алгоритма Дейкстры

У меня есть следующий алгоритм Дейкстры с тремя входными переменными (начало, останов и время). Для завершения требуется около 0,5-1 с. Мой хостинг-провайдер говорит, что он использует слишком много ресурсов, и я должен реализовать некоторый механизм кэширования. Мой вопрос, как?

Поскольку у меня есть 3 переменные, если только один из них изменяется – весь результат отличается (потому что у меня есть несколько дополнительных инструкций со временем, неважно). Итак, как реализовать некоторый механизм кэширования или сделать некоторую оптимизацию?

• Самый короткий путь на карте
• Более 640 000 элементов в массиве - проблема с памятью

У меня 1700 узлов .

<?php require_once("../includes/db_connection.php"); ?> <?php require("../includes/functions.php"); ?> <?php require("../includes/global_variables.php"); ?> <?php // Function to put "maxValues" into time (in my case 10 000 because I know it can't take longer than that from source to end node) function array_push_key(&$array, $key, $value) { $array[$key] = $value; } // Start the counter $timeM = microtime(); $timeM = explode(' ', $timeM); $timeM = $timeM[1] + $timeM[0]; $start = $timeM; // Get provided values $startStop = $_GET["start"]; $endStop = $_GET["end"]; $startTime = $_GET["time"]; // Initialize arrays $time = array(); $previousNode = array(); $allStops = array(); // [5] = 119 --> You can get to stop no. 5 by line no. 119 // line to source node is 0 $lineToThisStop = array(); $lineToThisStop[$startStop] = 0; // Populate arrays $result=mysql_query("SELECT stop_id FROM db_stops", $connection); potvrdi_unos($result); $counter = 0; while($rows = mysql_fetch_array($result)){ array_push_key($time, $rows["stop_id"], 10000); array_push($allStops, $rows["stop_id"]); // Locate startStop in the allStops array to unset it few lines later if ($rows["id"] == $startStop) { $poz = $brojac; } $counter++; } // Set starting time to starting stop $time[$startStop] = $startTime; // Set it activeNode $activeNode = $startStop; // Unset it in allStops array (so it doens't have to be checked later) unset($allStops[$poz]); $allStops = array_values($allStops); // I can put "while (true)" because all nodes are connected in "one piece", there is NO UNCONNECTED nodes while (true) { $result=mysql_query("SELECT route_id, next_stop FROM db_stop_times WHERE stop_id = $activeNode", $connection); potvrdi_unos($result); while($rows = mysql_fetch_array($result)) { // Draw paths from active node to all other (connected) stops $nextStopArray = $rows["next_stop"]; // nextStopArray is something like "0,34,123,3123,213" - those are all stops from current, active node/stop $nextStopArray = explode(",", $nextStopArray); // sometimes it's just "4" to convert it into array if (!is_array($nextStopArray)) { $nextStopArray[0] = $nextStopArray; } for ($p = 0; $p < sizeof($nextStopArray); $p++) { $nextStop = $nextStopArray[$p]; $walkToTheStop = false; // Few checks if ($p == 0) { if ($nextStop != 0) { $pathDuration = 2; if ($lineToThisStop[$activeNode] != $rows["route_id"]) { $pathDuration = $pathDuration * 2; } } } else { $walkToTheStop = true; $pathDuration = 1; } // If that's shortest path from ActiveNode to nextStop insert it into it's time array (time to get to that stop) if (($pathDuration + $time[$activeNode]) < $time[$nextStop]) { $time[$nextStop] = $pathDuration + $time[$activeNode]; array_push_key($previousNode, $nextStop, $activeNode); // Some aditional records (5000 means "you must walk to that stop") if ($walkToTheStop) { $lineToThisStop[$nextStop] = 5000; } else { $lineToThisStop[$nextStop] = $rows["route_id"]; } } } } // Traži slijedeću stanicu (vrh) s najmanjom vrijednosti $lowestValue = 10000 + 1; for ($j = 0; $j < sizeof($allStops); $j++) { if ($time[$allStops[$j]] < $lowestValue) { $lowestValue = $time[$allStops[$j]]; $activeNode = $allStops[$j]; // Record it's position so I can unset it later $activeNodePosition = $j; } } // Unset the active node from the array - so loop before will be shorter every time for one node/stop unset($allStops[$activeNodePosition]); $allStops = array_values($allStops); // If you get to the end stop, feel free to break out of the loop if ($activeNode == $endStop) { break; } } // How long did it take? $timeM = microtime(); $timeM = explode(' ', $timeM); $timeM = $timeM[1] + $timeM[0]; $finish = $timeM; $total_time = round(($finish - $start), 4); echo 'Total time '.$total_time.' seconds.'."<br />"; ?> <?php require_once("../includes/close_connection.php"); ?> 

 for ($p = 0; $p < sizeof($nextStopArray); $p++) { ... } 

 $nextStopArraySize = sizeof($nextStopArray); for ($p = 0; $p < $nextStopArraySize; ++$p) { ... } 

 for ($p = 0; $p < sizeof($nextStopArray); $p++) { 

 $nextStopArraySize = sizeof($nextStopArray); $p = -1 while (++$p < $nextStopArraySize) { ... } 

 $result=mysql_query("SELECT route_id, next_stop FROM db_stop_times WHERE stop_id = $activeNode", $connection); 

 while (true) { $result=mysql_query("SELECT route_id, next_stop FROM db_stop_times WHERE stop_id = $activeNode", $connection); 

 class Node { Link[] links; } class Link { int time; Node destination; }