Day 21 and 22 part1 in both of them works part2 is something quite different.

22/part1.php

@@ -0,0 +1,18 @@
+<?php
+$input = file('input', FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES);
+$array = [];
+foreach ($input as $line) {
+    echo "$line\n";
+    preg_match('#(?P<status>on|off) x=(-?\d*)..(-?\d*),y=(-?\d*)..(-?\d*),z=(-?\d*)..(-?\d*)#', $line, $found);
+    for ($x = (int)$found[2]; $x <= (int)$found[3]; $x++) {
+        for ($y = (int)$found[4]; $y <= (int)$found[5]; $y++) {
+            for ($z = (int)$found[6]; $z <= (int)$found[7]; $z++) {
+                unset($array[$x . '|' . $y . '|' . $z]);
+                if ($found['status'] == 'on') {
+                    $array[$x . '|' . $y . '|' . $z] = 1;
+                }
+            }
+        }
+    }
+}
+echo count($array); //644257