From 8b73ada230812c33e541ec8606311e59745f4ac5 Mon Sep 17 00:00:00 2001
From: Clement Desmidt <cdesmidt.ext@equad.fr>
Date: Wed, 10 Dec 2025 15:01:52 +0100
Subject: [PATCH] =?UTF-8?q?=E2=9C=A8=20Finit=20le=20jour=202=20et=20commen?=
 =?UTF-8?q?ce=20le=201=20et=20le=203?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .gitignore       |  2 ++
 add.sh           | 19 +++++++++++++++++++
 day_1/part_1.php | 35 +++++++++++++++++++++++++++++++++++
 day_2/part_1.php | 28 ++++++++++++++++++++++++++++
 day_2/part_2.php | 37 +++++++++++++++++++++++++++++++++++++
 day_3/part_1.php | 18 ++++++++++++++++++
 6 files changed, 139 insertions(+)
 create mode 100644 .gitignore
 create mode 100755 add.sh
 create mode 100644 day_1/part_1.php
 create mode 100644 day_2/part_1.php
 create mode 100644 day_2/part_2.php
 create mode 100644 day_3/part_1.php

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..d5a90de
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,2 @@
+input.txt
+/.idea
\ No newline at end of file
diff --git a/add.sh b/add.sh
new file mode 100755
index 0000000..df5c3ec
--- /dev/null
+++ b/add.sh
@@ -0,0 +1,19 @@
+#!/usr/bin/zsh
+
+SCRIPT_PATH="$( cd "$(dirname "$0")" ; pwd -P )"
+NUMBER=$1
+
+if [ ! -d "${SCRIPT_PATH}/day_${NUMBER}" ]; then
+  mkdir "${SCRIPT_PATH}/day_${NUMBER}"
+else
+  echo "folder ${SCRIPT_PATH}/day_${NUMBER} already exists"
+  exit
+fi
+
+cd "${SCRIPT_PATH}/day_${NUMBER}" || exit
+
+touch input.txt part_1.php part_2.php
+
+echo "DONE"
+
+exit
diff --git a/day_1/part_1.php b/day_1/part_1.php
new file mode 100644
index 0000000..5ae246d
--- /dev/null
+++ b/day_1/part_1.php
@@ -0,0 +1,35 @@
+<?php
+
+$lines = array_filter(explode("\n", file_get_contents(__DIR__.'/input.txt')), static fn($line) =>!empty($line));
+
+$count = 0;
+$position = 50;
+
+echo 'The dial starts by pointing at 50'."\n";
+
+function checkPosition(&$position)
+{
+    if ($position < 0) {
+        $position = 100 - abs($position);
+    } elseif ($position > 99) {
+        $position = $position - 100;
+    }
+}
+
+foreach ($lines as $line) {
+    $direction = substr($line, 0, 1);
+    $number = (int)substr($line, 1) % 100;
+    if ($direction === 'L') {
+        $position -= $number;
+        checkPosition($position);
+    } elseif ($direction === 'R') {
+        $position += $number;
+        checkPosition($position);
+    }
+
+    if ($position === 0) {
+        $count++;
+    }
+
+    echo sprintf('The dial is rotated %s to point at %u | count : %u%s', $line,$position, $count, "\n");
+}
\ No newline at end of file
diff --git a/day_2/part_1.php b/day_2/part_1.php
new file mode 100644
index 0000000..e0db408
--- /dev/null
+++ b/day_2/part_1.php
@@ -0,0 +1,28 @@
+<?php
+
+$intervals = array_map(fn($interval) => explode('-', $interval), explode(',', file_get_contents('./input.txt')));
+
+$invalids = [];
+
+foreach ($intervals as $interval) {
+    [$start, $end] = $interval;
+    $current = $start;
+    while ($current <= $end) {
+        if (is_invalid($current)) {
+            $invalids[] = $current;
+        }
+
+        $current++;
+    }
+}
+
+function is_invalid($current): bool {
+    if (strlen($current) % 2 !== 0) {
+        return false;
+    }
+
+    $middle = strlen($current) / 2;
+    return substr($current, 0, $middle) === substr($current, $middle);
+}
+
+echo array_sum($invalids);
\ No newline at end of file
diff --git a/day_2/part_2.php b/day_2/part_2.php
new file mode 100644
index 0000000..2d7bc47
--- /dev/null
+++ b/day_2/part_2.php
@@ -0,0 +1,37 @@
+<?php
+
+$intervals = array_map(fn($interval) => explode('-', $interval), explode(',', file_get_contents('./input.txt')));
+
+$invalids = [];
+
+foreach ($intervals as $interval) {
+    [$start, $end] = $interval;
+    $current = $start;
+    while ($current <= $end) {
+        if (is_invalid($current)) {
+            $invalids[] = $current;
+        }
+
+        $current++;
+    }
+}
+
+function is_invalid(string $current): bool {
+    for ($i = 1, $l = strlen($current); $i < $l; $i++) {
+        $parts = str_split($current, $i);
+        $is_equals = true;
+        for ($j = 0, $m = count($parts) - 1; $j < $m; $j++) {
+            if ($parts[$j] !== $parts[$j + 1]) {
+                $is_equals = false;
+                continue;
+            }
+        }
+        if ($is_equals) {
+            return true;
+        }
+    }
+
+    return false;
+}
+
+echo array_sum($invalids);
\ No newline at end of file
diff --git a/day_3/part_1.php b/day_3/part_1.php
new file mode 100644
index 0000000..7a8369b
--- /dev/null
+++ b/day_3/part_1.php
@@ -0,0 +1,18 @@
+<?php
+
+$banks = explode("\n", file_get_contents('./input.txt'));
+
+$output_joltage = [];
+
+foreach ($banks as $bank) {
+    $a_bank = str_split($bank);
+
+    $max = max(array_slice($a_bank,0,count($a_bank)-1));
+    $i = array_search($max, $a_bank);
+    $right_part = array_slice($a_bank, $i+1);
+    $max2 = max($right_part);
+
+    $output_joltage[] = (int) $max.$max2;
+}
+
+echo array_sum($output_joltage);
\ No newline at end of file