Day 13 Part 1

Day 13/Part_1.php

@@ -0,0 +1,36 @@
+<?php
+$in = file("input.txt", 2);
+$time = (int)$in[0];
+$range = explode(",", $in[1]);
+$ans = array();
+
+foreach ($range as $rk => $r) {
+    if ($r == "x") {
+        unset($range[$rk]);
+    }
+}
+
+function listtimes($bus,$time)
+{
+    $x = 0;
+    $a = array();
+    do {
+        if ($x % $bus == 0) {
+            array_push($a,$x);
+        }
+        $x++;
+    } while ($time + $bus > $x);
+    return end($a);
+}
+
+foreach ($range as $r) {
+    array_push($ans,array((int)$r,listtimes($r,$time) - $time));
+}
+
+function sortByOrder($a, $b) {
+    return $a[1] - $b[1];
+}
+
+usort($ans, 'sortByOrder');
+
+echo $ans[0][0] * $ans[0][1];

README.md

@@ -13,3 +13,4 @@
 |10|:heavy_check_mark:|:heavy_check_mark:|
 |11|:heavy_check_mark:|:heavy_check_mark:|
 |12|:heavy_check_mark:|:heavy_check_mark:|
+|13|:heavy_check_mark:|:x:|