day 1

public/Day.php

@@ -0,0 +1,16 @@
+<?php
+
+abstract class Day {
+
+	/* @var $input array<string> */
+	protected array $input;
+
+	public function __construct() {
+		$number = explode("Day", get_class($this))[1];
+
+		$this->input = explode("\n", file_get_contents("../input/$number.txt"), -1);
+	}
+
+	abstract function part1(): string;
+	abstract function part2(): string;
+}

public/days/Day1.php

@@ -0,0 +1,46 @@
+<?php
+
+final class Day1 extends Day {
+
+	function part1(): string {
+		$left = [];
+		$right = [];
+
+		foreach ($this->input as $line){
+			[$left[], $right[]] = array_map("intval", explode("   ", $line));
+		}
+
+		sort($left);
+		sort($right);
+
+		$sum = 0;
+
+		for ($i = 0; $i < count($left); $i++){
+			$sum += abs($left[$i] - $right[$i]);
+		}
+
+		return strval($sum);
+	}
+
+	function part2(): string {
+		$left = [];
+		$rightCounts = [];
+
+		foreach ($this->input as $line){
+			[$left[], $right] = array_map("intval", explode("   ", $line));
+			if (array_key_exists($right, $rightCounts)){
+				$rightCounts[$right]++;
+			} else {
+				$rightCounts[$right] = 1;
+			}
+		}
+
+		$sum = 0;
+
+		foreach ($left as $number){
+			$sum += $number * ($rightCounts[$number] ?? 0);
+		}
+
+		return strval($sum);
+	}
+}

public/fetch.php

@@ -8,7 +8,7 @@ foreach (parse_ini_file("../.env") as $key => $value){
 for ($i = 1; $i <= 25; $i++){
 	$context = stream_context_create([
 		'http' => [
-			'header' => 'Cookie: session=' . $_ENV["SESSION_COOKIE"] . '\r\n'
+			'header' => 'Cookie: session=' . $_ENV["SESSION_COOKIE"] . "\r\n"
 		]
 	]);
 	$contents = file_get_contents("https://adventofcode.com/2024/day/$i/input", context: $context);

public/run.php

@@ -0,0 +1,38 @@
+<?php
+
+header('Content-Type: application/json');
+
+require_once 'Day.php';
+
+$dayNumber = $_GET['day'] ?? null;
+$part = intval($_GET['part'] ?? 1);
+
+if ($dayNumber){
+	$file = "days/Day$dayNumber.php";
+	if (file_exists($file)){
+		require_once $file;
+		$class = "Day$dayNumber";
+
+		/* @var $day Day */
+		$day = new $class();
+
+		$method = "part$part";
+		if (method_exists($day, $method)){
+			$t1 = microtime(true);
+			$result = $day->$method();
+			$t2 = microtime(true);
+
+			$time = $t2 - $t1;
+
+			$response = [
+				'result' => $result,
+				'time' => $time,
+				'data' => null
+			];
+
+
+			echo json_encode($response);
+			die();
+		}
+	}
+}