From 4aaf8aca525e2a0335171a9fdc5151b020f2e044 Mon Sep 17 00:00:00 2001
From: Daniel Seiller <earthnuker@gmail.com>
Date: Sat, 3 Dec 2022 19:22:43 +0100
Subject: [PATCH] Day 02 optimizations + Day 03

---
 Cargo.toml   |  3 ++-
 src/day02.rs | 10 ++--------
 src/day03.rs | 46 ++++++++++++++++++++++++++++++++++++++++++++++
 src/dayXX.rs |  2 +-
 src/lib.rs   |  1 +
 5 files changed, 52 insertions(+), 10 deletions(-)
 create mode 100644 src/day03.rs

diff --git a/Cargo.toml b/Cargo.toml
index 60c494b..6aa112d 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -7,4 +7,5 @@ edition = "2021"
 
 [dependencies]
 aoc-runner = "0.3.0"
-aoc-runner-derive = "0.3.0"
\ No newline at end of file
+aoc-runner-derive = "0.3.0"
+itertools = "0.10.5"
diff --git a/src/day02.rs b/src/day02.rs
index 8b3be0a..59c0bae 100644
--- a/src/day02.rs
+++ b/src/day02.rs
@@ -16,10 +16,9 @@ pub enum Outcome {
     Draw,
 }
 
-
 impl Outcome {
     fn other(&self, choice: &Choice) -> Choice {
-        match (self,choice) {
+        match (self, choice) {
             (Outcome::Win, Choice::Rock) => Choice::Paper,
             (Outcome::Win, Choice::Paper) => Choice::Scissors,
             (Outcome::Win, Choice::Scissors) => Choice::Rock,
@@ -64,12 +63,10 @@ impl Choice {
             (Choice::Rock, Choice::Scissors) => Outcome::Win,
             (Choice::Paper, Choice::Rock) => Outcome::Win,
             (Choice::Scissors, Choice::Paper) => Outcome::Win,
-            (Choice::Rock, Choice::Rock) => Outcome::Draw,
-            (Choice::Paper, Choice::Paper) => Outcome::Draw,
-            (Choice::Scissors, Choice::Scissors) => Outcome::Draw,
             (Choice::Rock, Choice::Paper) => Outcome::Loose,
             (Choice::Paper, Choice::Scissors) => Outcome::Loose,
             (Choice::Scissors, Choice::Rock) => Outcome::Loose,
+            _ => Outcome::Draw,
         }
     }
 }
@@ -113,9 +110,6 @@ pub fn solve_part1(input: &[(Choice, Choice)]) -> usize {
         .sum()
 }
 
-
-
-
 #[aoc(day2, part2)]
 pub fn solve_part2(input: &[(Choice, Choice)]) -> usize {
     input
diff --git a/src/day03.rs b/src/day03.rs
new file mode 100644
index 0000000..1161d42
--- /dev/null
+++ b/src/day03.rs
@@ -0,0 +1,46 @@
+use aoc_runner_derive::{aoc, aoc_generator};
+use std::collections::HashSet;
+#[aoc_generator(day3)]
+pub fn input_generator(input: &str) -> Vec<Vec<char>> {
+    input.lines().map(|line| line.chars().collect()).collect()
+}
+
+#[aoc(day3, part1)]
+pub fn solve_part1(input: &[Vec<char>]) -> usize {
+    let mut total: usize = 0;
+    for line in input {
+        let (a, b) = line.split_at(line.len() / 2);
+        let a: HashSet<&char> = a.iter().collect();
+        let b: HashSet<&char> = b.iter().collect();
+        total += a
+            .intersection(&b)
+            .map(|&&v| match v {
+                'a'..='z' => 1 + ((v as u8) - b'a') as usize,
+                'A'..='Z' => 27 + ((v as u8) - b'A') as usize,
+                _ => unreachable!(),
+            })
+            .sum::<usize>();
+    }
+    total
+}
+
+#[aoc(day3, part2)]
+pub fn solve_part2(input: &[Vec<char>]) -> usize {
+    let mut total: usize = 0;
+    for chunk in input.chunks_exact(3) {
+        let chunk: HashSet<&char> = chunk
+            .iter()
+            .map(|v| v.iter().collect::<HashSet<&char>>())
+            .reduce(|a, b| a.intersection(&b).copied().collect())
+            .unwrap_or_default();
+        total += chunk
+            .iter()
+            .map(|&&v| match v {
+                'a'..='z' => 1 + ((v as u8) - b'a') as usize,
+                'A'..='Z' => 27 + ((v as u8) - b'A') as usize,
+                _ => unreachable!(),
+            })
+            .sum::<usize>();
+    }
+    total
+}
diff --git a/src/dayXX.rs b/src/dayXX.rs
index 83475ea..31eccf1 100644
--- a/src/dayXX.rs
+++ b/src/dayXX.rs
@@ -1,6 +1,6 @@
 use aoc_runner_derive::{aoc, aoc_generator};
 #[aoc_generator(dayX)]
-pub fn input_generator(input: &str) -> _ {
+pub fn input_generator(input: &str) -> usize {
     todo!()
 }
 
diff --git a/src/lib.rs b/src/lib.rs
index 290d5dd..6d55771 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,4 +1,5 @@
 use aoc_runner_derive::aoc_lib;
 pub mod day01;
 pub mod day02;
+pub mod day03;
 aoc_lib! { year = 2022 }