✨ Finit le jour 16

day_16/part_1.php

@@ -0,0 +1,58 @@
+<?php
+
+[$instructions, $mine, $others] = explode("\n\n", file_get_contents('input.txt'));
+
+// parse instructions
+function parseInstructions($instructions)
+{
+    // class: 1-3 or 5-7
+    preg_match_all('/^[a-z]+: (\d+)-(\d+) or (\d+)-(\d+)$/mi', $instructions, $matches);
+    if (count($matches) !== 5) {
+        echo sprintf('Regex failed : %s', var_export($matches, true));
+        exit;
+    }
+
+    $compares = [];
+    array_shift($matches);
+    for ($i = 0, $l = count($matches[0]); $i < $l; $i++) {
+        $compares[] = static function ($number) use ($matches, $i) {
+            $comparison = ($number >= (int)$matches[0][$i] and $number <= (int)$matches[1][$i])
+                || ($number >= (int)$matches[2][$i] and $number <= (int)$matches[3][$i]);
+            if ($comparison === true) {
+                return true;
+            }
+            return $number;
+        };
+    }
+
+    return $compares;
+}
+
+$compares = parseInstructions($instructions);
+
+// check others
+$others = explode("\n", $others);
+array_shift($others);
+$others = array_map(static function($other) {
+    return explode(',', $other);
+}, $others);
+
+$sum = 0;
+foreach ($others as $other) {
+    foreach ($other as $number) {
+        $is_valid = false;
+        foreach ($compares as $compare) {
+            if ($compare((int)$number) === true) {
+                $is_valid = true;
+                break;
+            }
+        }
+        if (!$is_valid) {
+            $sum += $number;
+            echo sprintf('%u not in comparison list%s', $number, "\n");
+        }
+    }
+}
+
+// sum it up
+echo $sum;