✨ Finit les 3e et 4e jours

2025-12-11 14:51:22 +01:00
parent 8b73ada230
commit 746ab0457a
3 changed files with 90 additions and 0 deletions
--- a/day_4/part_1.php
+++ b/day_4/part_1.php
@@ -0,0 +1,54 @@
+<?php
+
+$grid = array_map(fn($line) => str_split($line), array_filter(explode("\n", file_get_contents(__DIR__.'/input.txt')), static fn($line) =>!empty($line)));
+
+$count = 0;
+
+do {
+    $local_count = 0;
+    $removed_papers = [];
+    foreach ($grid as $i => $line) {
+        foreach ($line as $j => $cell) {
+            switch ($cell) {
+                case '@':
+                    if (count_adjacents($i, $j) < 4) {
+                        $local_count++;
+                        $removed_papers[] = [$i, $j];
+                    }
+                    break;
+                case '.':
+                default:
+                    break;
+            }
+        }
+    }
+
+    foreach ($removed_papers as $removed_paper) {
+        $grid[$removed_paper[0]][$removed_paper[1]] = '.';
+    }
+
+    $count += $local_count;
+} while ($local_count !== 0);
+
+echo $count;
+
+function count_adjacents(int $i, int $j): int
+{
+    global $grid;
+    $count = 0;
+    if (array_key_exists($i - 1, $grid)) {
+        if (array_key_exists($j - 1, $grid[$i - 1]) && $grid[$i - 1][$j - 1] === '@') $count++;
+        if ($grid[$i - 1][$j] === '@') $count++;
+        if (array_key_exists($j + 1, $grid[$i - 1]) && $grid[$i - 1][$j + 1] === '@') $count++;
+    }
+
+    if (array_key_exists($j - 1, $grid[$i]) && $grid[$i][$j - 1] === '@') $count++;
+    if (array_key_exists($j + 1, $grid[$i]) && $grid[$i][$j + 1] === '@') $count++;
+
+    if (array_key_exists($i + 1, $grid)) {
+        if (array_key_exists($j - 1, $grid[$i + 1]) && $grid[$i + 1][$j - 1] === '@') $count++;
+        if ($grid[$i + 1][$j] === '@') $count++;
+        if (array_key_exists($j + 1, $grid[$i + 1]) && $grid[$i + 1][$j + 1] === '@') $count++;
+    }
+    return $count;
+}