From ec95bf332c5b01b0569e8fa6e82d9937c99354dd Mon Sep 17 00:00:00 2001
From: Clement Desmidt <clement@desmidt.fr>
Date: Wed, 15 Dec 2021 12:37:46 +0100
Subject: [PATCH] :sparkles: Ajoute le jour 14

---
 day_14/part_1.php | 30 ++++++++++++++++++++++++++
 day_14/part_2.php | 55 +++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 85 insertions(+)
 create mode 100644 day_14/part_1.php
 create mode 100644 day_14/part_2.php

diff --git a/day_14/part_1.php b/day_14/part_1.php
new file mode 100644
index 0000000..f806923
--- /dev/null
+++ b/day_14/part_1.php
@@ -0,0 +1,30 @@
+<?php
+
+[$template, $rules] = explode("\n\n", file_get_contents('./input.txt'));
+
+$template = str_split($template);
+
+$pair_insertion_rules = [];
+foreach (explode("\n", $rules) as $rule) {
+    [$key, $value] = explode(' -> ', $rule);
+    $pair_insertion_rules[$key] = $value;
+}
+
+for ($i = 0; $i < 40; $i++) {
+    $tmp = [];
+    foreach ($template as $i_char => $char) {
+        if (array_key_exists($i_char+1, $template)) {
+            $tmp[] = $char;
+            $pair = $char . $template[$i_char + 1];
+            if (array_key_exists($pair, $pair_insertion_rules)) {
+                $tmp[] = $pair_insertion_rules[$pair];
+            }
+        }
+    }
+    $tmp[] = array_pop($template);
+    $template = $tmp;
+    echo $i."\n";
+}
+
+$count_char = array_count_values($template);
+echo max($count_char) - min($count_char);
diff --git a/day_14/part_2.php b/day_14/part_2.php
new file mode 100644
index 0000000..0e2567b
--- /dev/null
+++ b/day_14/part_2.php
@@ -0,0 +1,55 @@
+<?php
+
+[$template, $rules] = explode("\n\n", file_get_contents('./input.txt'));
+
+$template = str_split($template);
+
+$pair_insertion_rules = [];
+foreach (explode("\n", $rules) as $rule) {
+    [$key, $value] = explode(' -> ', $rule);
+    $pair_insertion_rules[$key] = $value;
+}
+
+$pair_counts = count_pairs($template);
+
+for ($i = 0; $i < 40; $i++) {
+    $new_pair_counts = $pair_counts;
+    foreach ($pair_counts as $key => $value) {
+        $substitute = $pair_insertion_rules[$key];
+        $pair1 = $key[0] . $substitute;
+        $pair2 = $substitute . $key[1];
+
+        $new_pair_counts[$pair1] = array_key_exists($pair1, $new_pair_counts) ? $new_pair_counts[$pair1] + $value : $value;
+        $new_pair_counts[$pair2] = array_key_exists($pair2, $new_pair_counts) ? $new_pair_counts[$pair2] + $value : $value;
+        $new_pair_counts[$key] = $new_pair_counts[$key] - $value;
+        if ($new_pair_counts[$key] < 1) {
+            unset($new_pair_counts[$key]);
+        }
+    }
+    $pair_counts = $new_pair_counts;
+}
+
+$count_elements = [];
+foreach ($pair_counts as $pair => $pair_count) {
+    foreach (str_split($pair) as $element) {
+        $count_elements[$element] = array_key_exists($element, $count_elements) ? $count_elements[$element] + $pair_count : $pair_count;
+    }
+}
+
+array_walk($count_elements, static function (&$count_element) {
+    $count_element = ceil($count_element / 2);
+});
+
+function count_pairs($template): array
+{
+    $counts = [];
+    for ($i = 0; $i < count($template) - 1; $i++) {
+        $pair = $template[$i] . $template[$i + 1];
+        $counts[$pair] = array_key_exists($pair, $counts) ? $counts[$pair]+1 : 1;
+    }
+
+    return $counts;
+}
+
+echo max($count_elements) - min($count_elements);
+