5th day 1st part

05/part1.php

@@ -0,0 +1,25 @@
+<?php
+echo '<pre>';
+$input = file('input', FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES);
+$input = array_map(fn($line) => explode(',', str_replace(' -> ', ',', $line)), $input);
+
+$map = array_fill(0, 1000, array_fill(0, 1000, 0));
+
+foreach ($input as $coordinates) {
+    if ($coordinates[0] == $coordinates[2]) {
+        $start = min([$coordinates[1], $coordinates[3]]);
+        $end = max([$coordinates[1], $coordinates[3]]);
+        for ($i = $start; $i <= $end; $i++) {
+            $map[$coordinates[0]][$i]++;
+        }
+    }
+    if ($coordinates[1] == $coordinates[3]) {
+        $start = min([$coordinates[0], $coordinates[2]]);
+        $end = max([$coordinates[0], $coordinates[2]]);
+        for ($i = $start; $i <= $end; $i++) {
+            $map[$i][$coordinates[1]]++;
+        }
+    }
+}
+echo count(array_filter(call_user_func_array('array_merge', $map), fn($el) => $el > 1)); //5632
+