From cf8f487526d484b446a33bf7f39d138e95380c6a Mon Sep 17 00:00:00 2001
From: spamegg <spamegg@pm.me>
Date: Sun, 1 Dec 2024 09:06:02 +0300
Subject: [PATCH 1/3] Solution article for 2024 Day 01

- Also added link to my community solution
---
 docs/2024/puzzles/day01.md | 62 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 62 insertions(+)

diff --git a/docs/2024/puzzles/day01.md b/docs/2024/puzzles/day01.md
index a207fe083..1500d11d7 100644
--- a/docs/2024/puzzles/day01.md
+++ b/docs/2024/puzzles/day01.md
@@ -6,7 +6,69 @@ import Solver from "../../../../../website/src/components/Solver.js"
 
 https://adventofcode.com/2024/day/1
 
+## Solution Summary
+
+1. Parse the input to split it into two lists (left/right), each sorted in increasing order.
+2. Find the distance scores (for `part1`) and the similarity scores (for `part2`).
+3. Sum the scores.
+
+### Parsing
+
+Our parser iterates over the lines, extracts the pair of numbers from each line,
+then splits them into two lists (lefts and rights), and separately sorts the lists.
+Therefore it looks like this:
+
+```scala
+def parse(input: String): (Seq[Long], Seq[Long]) =
+  // Extract pairs of numbers from each line
+  val pairs = input
+    .linesIterator
+    .map(line => line.split("   ").map(_.toLong))
+    .toSeq
+
+  // Group the left and right members from each pair, sort them
+  val lefts = pairs.map(_.head).toSeq.sorted
+  val rights = pairs.map(_.last).toSeq.sorted
+  (lefts, rights)
+```
+
+### Part 1
+
+Now that the lefts and rights are sorted in increasing order, we can zip them,
+so that the first smallest on the left is paired with the first smallest on the right,
+the second smallest on the left is paired with the second smallest on the right, and so on.
+Then we can find the distances between them, and sum the distances:
+
+```scala
+def part1(input: String): String =
+  val (lefts, rights) = parse(input)
+  lefts
+    .zip(rights)
+    .map((left, right) => math.abs(left - right)) // distances
+    .sum
+end part1
+```
+
+### Part 2
+
+Very similar, but instead of distances, we find a left number's similarity on the right list.
+We do this by counting how many times the left number occurs on the right list,
+then multiply that count by the number itself.
+Finally we sum the similarity scores of all the left numbers:
+
+```scala
+def part2(input: String): String =
+  val (lefts, rights) = parse(input)
+  lefts
+    .map(left => rights.count(_ == left) * left) // similarity scores
+    .sum
+end part2
+```
+
+
 ## Solutions from the community
 
+- [Solution](https://github.com/spamegg1/aoc/blob/master/2024/01/01.worksheet.sc#L122) by [Spamegg](https://github.com/spamegg1/)
+
 Share your solution to the Scala community by editing this page.
 You can even write the whole article! [See here for the expected format](https://github.com/scalacenter/scala-advent-of-code/discussions/424)

From df1f996d0ad1086d58e4643b9c6797c86c3a62fd Mon Sep 17 00:00:00 2001
From: spamegg <spamegg@pm.me>
Date: Sun, 1 Dec 2024 18:25:03 +0300
Subject: [PATCH 2/3] Apply suggestions from code review

Co-authored-by: Jamie Thompson <bishbashboshjt@gmail.com>
---
 docs/2024/puzzles/day01.md | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/docs/2024/puzzles/day01.md b/docs/2024/puzzles/day01.md
index 1500d11d7..dfb2e4e19 100644
--- a/docs/2024/puzzles/day01.md
+++ b/docs/2024/puzzles/day01.md
@@ -40,7 +40,7 @@ the second smallest on the left is paired with the second smallest on the right,
 Then we can find the distances between them, and sum the distances:
 
 ```scala
-def part1(input: String): String =
+def part1(input: String): Long =
   val (lefts, rights) = parse(input)
   lefts
     .zip(rights)
@@ -57,7 +57,7 @@ then multiply that count by the number itself.
 Finally we sum the similarity scores of all the left numbers:
 
 ```scala
-def part2(input: String): String =
+def part2(input: String): Long =
   val (lefts, rights) = parse(input)
   lefts
     .map(left => rights.count(_ == left) * left) // similarity scores

From 731def27901dc66b6945cbd60d088e21e4ca4e79 Mon Sep 17 00:00:00 2001
From: spamegg <spamegg@pm.me>
Date: Mon, 2 Dec 2024 18:27:44 +0300
Subject: [PATCH 3/3] added author name

---
 docs/2024/puzzles/day01.md | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/docs/2024/puzzles/day01.md b/docs/2024/puzzles/day01.md
index aacf5f2d6..5d0df78c5 100644
--- a/docs/2024/puzzles/day01.md
+++ b/docs/2024/puzzles/day01.md
@@ -2,6 +2,8 @@ import Solver from "../../../../../website/src/components/Solver.js"
 
 # Day 1: Historian Hysteria
 
+by [@spamegg1](https://github.com/spamegg1)
+
 ## Puzzle description
 
 https://adventofcode.com/2024/day/1