3rd and 2nd day

01/part2.php

@@ -0,0 +1,18 @@
+<?php
+/**
+ *
+ */
+
+$input = file('input', FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES);
+$input = array_map('intval', $input);
+
+$increased       = 0;
+$previousReading = array_sum(array_slice($input, 0, 3));
+for ($i = 1; $i < count($input) - 2; $i++) {
+    $currentReading = array_sum(array_slice($input, $i, 3));
+    if ($currentReading > $previousReading) {
+        $increased++;
+    }
+    $previousReading = $currentReading;
+}
+echo $increased; // 1597