✨ Add day 8

.gitignore

@@ -1,2 +1,3 @@
 input.txt
 /.idea
+/day_8/part_2.png

day_8/part_1.php

@@ -0,0 +1,25 @@
+<?php
+
+$input = file_get_contents('input.txt');
+
+const WIDTH = 25;
+const HEIGHT = 6;
+$area = WIDTH * HEIGHT;
+
+$layers = array_map(static function($layer) {
+    return str_split($layer);
+}, str_split($input, $area));
+
+usort($layers, function($layer_a, $layer_b) {
+    $a0 = array_count_values($layer_a)['0'];
+    $b0 = array_count_values($layer_b)['0'];
+    if ($a0 === $b0) {
+        return 0;
+    }
+    return  $a0 < $b0 ? -1 : 1 ;
+});
+
+reset($layers);
+$fewest_0_layer = current($layers);
+
+echo array_count_values($fewest_0_layer)['1'] * array_count_values($fewest_0_layer)['2'];

day_8/part_2.php

@@ -0,0 +1,68 @@
+<?php
+
+$input = file_get_contents('input.txt');
+
+const TRANSPARENT = 2;
+const WHITE = 1;
+const BLACK = 0;
+const WIDTH = 25;
+const HEIGHT = 6;
+$area = WIDTH * HEIGHT;
+
+function flatten(array $array) {
+    $return = [];
+
+    array_walk_recursive($array, static function($a) use (&$return) { $return[] = $a; });
+
+    return implode('', $return);
+}
+
+$layers = array_map(static function($layer) {
+    return str_split($layer, WIDTH);
+}, str_split($input, $area));
+
+$final_image = array_fill(0, HEIGHT, []);
+$final_image = array_map(static function() {
+    return array_fill(0, WIDTH, TRANSPARENT);
+}, $final_image);
+
+foreach ($layers as $layer) {
+    foreach ($layer as $row => $line) {
+        $numbers = str_split($line);
+        foreach ($numbers as $col => $number) {
+            if ($final_image[$row][$col] == TRANSPARENT) {
+                $final_image[$row][$col] = $number;
+            }
+        }
+    }
+}
+
+$image = new Imagick();
+
+$white = new \ImagickPixel('#FFFFFF');
+$black = new \ImagickPixel('#000000');
+
+$image->newImage(WIDTH * 10, HEIGHT * 10, 'none');
+$image->setImageFormat('png');
+
+$draw = new \ImagickDraw();
+
+foreach ($final_image as $j => $row) {
+    foreach ($row as $i => $cell) {
+        $color = 'none';
+        if ($cell == WHITE) {
+            $color = $white;
+        }
+        if ($cell == BLACK) {
+            $color = $black;
+        }
+        $draw->setFillColor($color);
+        $draw->rectangle(10 * $i, 10 * $j, 10 * $i + 10, 10 * $j + 10);
+    }
+}
+
+$image->drawImage($draw);
+
+header("Content-Type: image/png");
+$data = $image->getImageBlob();
+file_put_contents('part_2.png', $data);