day 2

2 files changed, 117 insertions, 0 deletions

diff --git a/src/bin/2023/day2.rs b/src/bin/2023/day2.rs
new file mode 100644
index 0000000..3a12adb
--- /dev/null
+++ b/src/bin/2023/day2.rs
@@ -0,0 +1,115 @@
+#![allow(dead_code)]
+#![allow(unused_variables)]
+
+use std::str::FromStr;
+
+use advent_of_code::prelude::*;
+
+#[derive(Clone, Copy, Debug)]
+pub enum Color {
+    Red(i64),
+    Green(i64),
+    Blue(i64),
+}
+
+impl FromStr for Color {
+    type Err = anyhow::Error;
+
+    fn from_str(s: &str) -> std::result::Result<Self, Self::Err> {
+        let parts: Vec<_> = s.split(' ').collect();
+        match parts[1] {
+            "red" => Ok(Self::Red(parts[0].parse()?)),
+            "green" => Ok(Self::Green(parts[0].parse()?)),
+            "blue" => Ok(Self::Blue(parts[0].parse()?)),
+            _ => Err(anyhow::anyhow!("failed to parse {}", parts[1])),
+        }
+    }
+}
+
+pub fn parse(fh: File) -> Result<Vec<Vec<Vec<Color>>>> {
+    parse::raw_lines(fh)
+        .map(|line| {
+            let line = line.split(": ").nth(1).unwrap();
+            line.split("; ")
+                .map(|draw| {
+                    draw.split(", ")
+                        .map(|color| color.parse::<Color>())
+                        .collect::<Result<Vec<_>, _>>()
+                })
+                .collect::<Result<Vec<Vec<_>>, _>>()
+        })
+        .collect()
+}
+
+pub fn part1(games: Vec<Vec<Vec<Color>>>) -> Result<i64> {
+    let mut total = 0;
+    'game: for (i, game) in games.into_iter().enumerate() {
+        for draw in game {
+            for color in draw {
+                match color {
+                    Color::Red(n) => {
+                        if n > 12 {
+                            continue 'game;
+                        }
+                    }
+                    Color::Green(n) => {
+                        if n > 13 {
+                            continue 'game;
+                        }
+                    }
+                    Color::Blue(n) => {
+                        if n > 14 {
+                            continue 'game;
+                        }
+                    }
+                }
+            }
+        }
+        total += i64::try_from(i).unwrap() + 1;
+    }
+    Ok(total)
+}
+
+pub fn part2(games: Vec<Vec<Vec<Color>>>) -> Result<i64> {
+    let mut total = 0;
+    for game in games {
+        let mut min_red = 0;
+        let mut min_green = 0;
+        let mut min_blue = 0;
+        for draw in game {
+            for color in draw {
+                match color {
+                    Color::Red(n) => {
+                        if n > min_red {
+                            min_red = n;
+                        }
+                    }
+                    Color::Green(n) => {
+                        if n > min_green {
+                            min_green = n;
+                        }
+                    }
+                    Color::Blue(n) => {
+                        if n > min_blue {
+                            min_blue = n;
+                        }
+                    }
+                }
+            }
+        }
+        total += min_red * min_green * min_blue;
+    }
+    Ok(total)
+}
+
+#[test]
+fn test() {
+    assert_eq!(
+        part1(parse(parse::data(2023, 2).unwrap()).unwrap()).unwrap(),
+        2617
+    );
+    assert_eq!(
+        part2(parse(parse::data(2023, 2).unwrap()).unwrap()).unwrap(),
+        59795
+    );
+}
diff --git a/src/bin/2023/main.rs b/src/bin/2023/main.rs
index 01e0de3..cb9aa54 100644
--- a/src/bin/2023/main.rs
+++ b/src/bin/2023/main.rs
@@ -12,6 +12,7 @@
 use advent_of_code::prelude::*;
 
 mod day1;
+mod day2;
 // NEXT MOD
 
 #[paw::main]
@@ -19,6 +20,7 @@ fn main(opt: Opt) -> Result<()> {
     #[allow(clippy::match_single_binding)]
     match opt.day {
         1 => advent_of_code::day!(2023, opt.day, opt.puzzle, day1),
+        2 => advent_of_code::day!(2023, opt.day, opt.puzzle, day2),
         // NEXT PART
         _ => panic!("unknown day {}", opt.day),
     }