hsegnitz
diff --git a/‎php/2024/06/01.php
Lines changed: 53 additions & 0 deletions b/‎php/2024/06/01.php
Lines changed: 53 additions & 0 deletions
diff --git a/‎php/2024/06/example.txt
132 Bytes b/‎php/2024/06/example.txt
132 Bytes
diff --git a/‎php/2024/06/input.txt
16.7 KB b/‎php/2024/06/input.txt
16.7 KB
@@ -0,0 +1,53 @@
+<?php
+
+$start = microtime(true);
+
+#$lines = file('example.txt', FILE_IGNORE_NEW_LINES);
+$lines = file('input.txt', FILE_IGNORE_NEW_LINES);
+
+
+$map = [];
+$currentRow = $currentCol = 0;
+foreach ($lines as $line) {
+    if (false !== ($found = strpos($line, '^'))) {
+        $currentRow = count($map);
+        $currentCol = $found;
+    }
+    $map[] = str_split($line);
+}
+
+// N = 0, E = 1, S = 2, W = 3
+$directions = [
+    0 => [0, -1],
+    1 => [1,  0],
+    2 => [0,  1],
+    3 => [-1, 0],
+];
+$facing = 0;
+
+
+$visitedPos = [
+    "{$currentCol}x{$currentRow}" => true,
+];
+while (true) {
+    $newCol = $currentCol + $directions[$facing][0];
+    $newRow = $currentRow + $directions[$facing][1];
+
+    if (!isset($map[$newRow][$newCol])) {
+        break;
+    }
+    if ($map[$newRow][$newCol] === '#') {
+        $facing = ++$facing % 4;
+        continue;
+    }
+
+    $currentRow = $newRow;
+    $currentCol = $newCol;
+    $visitedPos["{$currentCol}x{$currentRow}"] = true;
+}
+
+
+echo count($visitedPos), "\n";
+
+echo microtime(true) - $start;
+echo "\n";