Improve hand creation

Cargo.toml

@@ -10,30 +10,30 @@ chrono = "0.4.23"
 regex = "1.7.0"
 
 [features]
-default = ["a", "b", "today"]
-a = []
-b = []
+default = ["part1", "part2", "today"]
+part1 = []
+part2 = []
 today = []
-01 = []
-02 = []
-03 = []
-04 = []
-05 = []
-06 = []
-07 = []
-08 = []
-09 = []
-10 = []
-11 = []
-12 = []
-13 = []
-14 = []
-15 = []
-16 = []
-17 = []
-18 = []
-19 = []
-20 = []
+day01 = []
+day02 = []
+day03 = []
+day04 = []
+day05 = []
+day06 = []
+day07 = []
+day08 = []
+day09 = []
+day10 = []
+day11 = []
+day12 = []
+day13 = []
+day14 = []
+day15 = []
+day16 = []
+day17 = []
+day18 = []
+day19 = []
+day20 = []
 
 
 

src/day01/mod.rs

@@ -2,4 +2,29 @@ use crate::read;
 
 pub fn run() {
     let input = read("01");
+    let elves = vec![0];
+
+    let mut elves = input.lines().fold(elves, |mut acc, x|{
+        if x.is_empty() {
+            acc.push(0);
+        } else {
+            let num: i32 = x.parse().unwrap();
+            *acc.last_mut().unwrap() += num;
+        }
+        acc
+    });
+    elves.sort();
+    elves.reverse();
+
+    #[cfg(feature="part1")]
+    {
+        let a = elves.first().unwrap();
+        eprintln!("Part 01: {}", *a);
+    }
+
+    #[cfg(feature="part2")]
+    {
+        let b = elves[..3].iter().sum::<i32>();
+        eprintln!("Part 02: {}", b);
+    }
 }

src/day02/mod.rs

@@ -0,0 +1,107 @@
+use crate::read;
+
+#[derive(Clone)]
+struct Hand {
+    pub letter: char
+}
+
+impl From<&str> for Hand {
+    fn from(s: &str) -> Self {
+        Self { letter: s.0.chars().next().unwrap() }
+    }
+}
+
+impl Hand {
+    pub fn score(&self) -> i32 {
+        match self.letter {
+            'A' => 1,
+            'B' => 2,
+            'C' => 3,
+            'X' => 1,
+            'Y' => 2,
+            'Z' => 3,
+            _ => panic!("Unknown hand {}", self.letter)
+        }
+    }
+
+    pub fn outcome(&self, other: &Hand) -> i32 {
+        match self.score() - other.score() {
+            -1 => 0,
+            -2 => 6,
+            0 => 3,
+            1 => 6,
+            2 => 0,
+            _ => panic!("Unknown match {} vs {}", self.letter, other.letter)
+        }
+    }
+
+    pub fn outcome_b(&self) -> i32 {
+        match self.letter {
+            'X' => 0,
+            'Y' => 3,
+            'Z' => 6,
+            _ => panic!("Unknown outcome {}", self.letter)
+        }
+    }
+
+    pub fn for_outcome(&self, enemy: &Hand) -> Self {
+        let letter = match (self.outcome_b(), enemy.letter) {
+            (o, l) if o == 3 => l,
+            (o, l) if o == 0 && l == 'A' => 'C',
+            (o, l) if o == 0 && l == 'B' => 'A',
+            (o, l) if o == 0 && l == 'C' => 'B',
+            (o, l) if o == 6 && l == 'A' => 'B',
+            (o, l) if o == 6 && l == 'B' => 'C',
+            (o, l) if o == 6 && l == 'C' => 'A',
+            (o, l)=> panic!("Unknown pairing {}/{}", o, l)
+        };
+       Self {
+           letter
+       }
+    }
+}
+
+struct Round {
+    pub enemy: Hand,
+    pub me: Hand,
+}
+
+impl Round {
+    pub fn score(&self) -> i32 {
+        self.me.score() + self.me.outcome(&self.enemy)
+    }
+
+    pub fn score_b(&self) -> i32 {
+        let me = self.me.for_outcome(&self.enemy);
+        me.score() + self.me.outcome_b()
+    }
+}
+
+pub fn run() {
+    let input = read("02");
+    let rounds = input
+        .lines()
+        .map(|l| {
+            let hands = l
+                .split_once(' ')
+                .map(|c|
+                    (c.0.into(),
+                     c.1.into())
+                ).unwrap();
+            Round {
+                enemy: hands.0,
+                me: hands.1,
+            }
+        }).map(|r|(r.score(), r.score_b()))
+        .fold((0, 0), |agg, cur|(agg.0 + cur.0, agg.1 + cur.1));
+
+    #[cfg(feature = "part1")]
+    {
+        eprintln!("Day 2, Part 01: {}", rounds.0);
+    }
+
+    #[cfg(feature = "part2")]
+    {
+        eprintln!("Day 2, Part 02: {}", rounds.1);
+    }
+}

src/main.rs

@@ -1,7 +1,8 @@
+use chrono::prelude::*;
 use std::path::Path;
 use std::time::Instant;
-use chrono::prelude::*;
 mod day01;
+mod day02;
 
 fn main() {
     let today = Local::now().day();
@@ -10,8 +11,7 @@ fn main() {
         day01::run();
     }
     if cfg!(feature = "day02") || (cfg!(feature = "today") && today == 2) {
-        todo!()
-        //day02::run();
+        day02::run();
     }
     println!("Finished, time taken: {:?}", now.elapsed())
 }