🎉 initialise le repo comme en 2020 et 2019

day_1/part_1.php

@@ -0,0 +1,15 @@
+<?php
+
+$numbers = array_map('intval', explode("\n", file_get_contents('input.txt')));
+
+$current = array_shift($numbers);
+$count = 0;
+foreach ($numbers as $number) {
+    if ($number > $current) {
+        $count++;
+    }
+
+    $current = $number;
+}
+
+echo $count;

day_1/part_2.php

@@ -0,0 +1,18 @@
+<?php
+
+$numbers = array_map('intval', explode("\n", file_get_contents('input.txt')));
+
+$current_slice = array_sum(array_slice($numbers, 0, 3));
+
+$count = 0;
+
+for ($i = 1, $l = count($numbers) - 3; $i <= $l; $i++) {
+    $new_slice = array_sum(array_slice($numbers, $i, 3));
+    if ($new_slice > $current_slice) {
+        $count++;
+    }
+
+    $current_slice = $new_slice;
+}
+
+echo $count;