✨ Finit le jour 5

day_5/part_1.php

@@ -0,0 +1,46 @@
+<?php
+
+$coordinates = array_map(static function ($line) {
+    preg_match('/^(\d+),(\d+) -> (\d+),(\d+)$/', $line, $matches);
+    array_shift($matches);
+    return $matches;
+}, explode("\n", file_get_contents('./input.txt')));
+
+$grid = array_fill(0, 1000, array_fill(0, 1000, 0));
+
+foreach ($coordinates as $coordinate) {
+    if (is_horizontal($coordinate)) {
+        $axis = $coordinate[0];
+        $min = min($coordinate[1], $coordinate[3]);
+        $max = max($coordinate[1], $coordinate[3]);
+        for ($i = $min; $i <= $max; $i++) {
+            $grid[$axis][$i]++;
+        }
+    } elseif (is_vertical($coordinate)) {
+        $axis = $coordinate[1];
+        $min = min($coordinate[0], $coordinate[2]);
+        $max = max($coordinate[0], $coordinate[2]);
+        for ($i = $min; $i <= $max; $i++) {
+            $grid[$i][$axis]++;
+        }
+    }
+}
+
+$count = 0;
+foreach ($grid as $row) {
+    $count += count(array_filter($row, static function($cell) {
+        return $cell >= 2;
+    }));
+}
+
+echo $count;
+
+function is_horizontal($coordinate)
+{
+    return $coordinate[0] === $coordinate[2];
+}
+
+function is_vertical($coordinate)
+{
+    return $coordinate[1] === $coordinate[3];
+}