From 959cb8fd586a60bbcdb09ec730971df713ae0087 Mon Sep 17 00:00:00 2001
From: Joe Hildebrand <joe-github@cursive.net>
Date: Thu, 5 Dec 2024 00:27:18 -0800
Subject: [PATCH] Day 5

---
 day5.peggy   | 10 ++++++++++
 day5.ts      | 36 ++++++++++++++++++++++++++++++++++++
 inputs       |  2 +-
 test/day5.js |  1 +
 4 files changed, 48 insertions(+), 1 deletion(-)
 create mode 100644 day5.peggy
 create mode 100644 day5.ts
 create mode 100644 test/day5.js

diff --git a/day5.peggy b/day5.peggy
new file mode 100644
index 0000000..9301963
--- /dev/null
+++ b/day5.peggy
@@ -0,0 +1,10 @@
+manual = @order "\n" @pages
+
+order = (@num "|" @num "\n")*
+
+pages = (@page "\n")+
+
+page = num|1.., ","|
+
+num = n:$[0-9]+ { return parseInt(n, 10) }
+_ = [ \t]+
diff --git a/day5.ts b/day5.ts
new file mode 100644
index 0000000..15473a1
--- /dev/null
+++ b/day5.ts
@@ -0,0 +1,36 @@
+import { type MainArgs, parseFile } from './lib/utils.ts';
+
+type Parsed = [[number, number][], number[][]];
+
+function part1(inp: number[][][]): number {
+  return inp
+    .filter(([before, after]) => before.join(',') === after.join(','))
+    .reduce((t, [before]) => t + before[Math.floor(before.length / 2)], 0);
+}
+
+function part2(inp: number[][][]): number {
+  return inp
+    .filter(([before, after]) => before.join(',') !== after.join(','))
+    .reduce((t, [_, after]) => t + after[Math.floor(after.length / 2)], 0);
+}
+
+export default async function main(args: MainArgs): Promise<[number, number]> {
+  const inp = await parseFile<Parsed>(args);
+  const order = new Set<string>();
+  for (const [x, y] of inp[0]) {
+    order.add(`${x},${y}`);
+  }
+  const beforeAndAfter = inp[1].map((pages) => {
+    const sorted = [...pages].sort((a, b) => {
+      if (order.has(`${a},${b}`)) {
+        return -1;
+      }
+      if (order.has(`${b},${a}`)) {
+        return 1;
+      }
+      return 0;
+    });
+    return [pages, sorted];
+  });
+  return [part1(beforeAndAfter), part2(beforeAndAfter)];
+}
diff --git a/inputs b/inputs
index f9def56..545dfbe 160000
--- a/inputs
+++ b/inputs
@@ -1 +1 @@
-Subproject commit f9def56e294696296806761bc751e9cddc7a79be
+Subproject commit 545dfbe8c1614e19ca6e08fe010b399ffaa355d0
diff --git a/test/day5.js b/test/day5.js
new file mode 100644
index 0000000..c013dd8
--- /dev/null
+++ b/test/day5.js
@@ -0,0 +1 @@
+export default [4662, 5900];