Solution to the first puzzle of Advent of Code 2021. pog

.idea/.gitignore

@@ -0,0 +1,9 @@
+# Default ignored files
+/shelf/
+/workspace.xml
+# Editor-based HTTP Client requests
+/httpRequests/
+# Datasource local storage ignored files
+/dataSources/
+/dataSources.local.xml
+.idea

01/index.php

@@ -0,0 +1,17 @@
+<?php
+/**
+ *
+ */
+
+$increased = 0;
+$inputStream = fopen('input', 'r');
+$previousReading = (int)fgets($inputStream);
+while (($line = fgets($inputStream)) !== false) {
+    $line = (int)$line;
+    if ($line > $previousReading) {
+        $increased++;
+    }
+    $previousReading = $line;
+}
+fclose($inputStream);
+echo $increased; //1553