day03 finished

src/days/day01/mod.rs

@@ -1,7 +1,6 @@
 use itertools::Itertools;
 use std::num::ParseIntError;
 
-use anyhow::Result;
 use thiserror::Error;
 
 use super::template::{DayTrait, ResultType};
@@ -14,13 +13,13 @@ impl DayTrait for Day {
         DAY_NUMBER
     }
 
-    fn part1(&self, lines: &str) -> Result<ResultType> {
+    fn part1(&self, lines: &str) -> anyhow::Result<ResultType> {
         let vector = Day::parse(lines)?;
         let max = vector.iter().max().ok_or(CalorieError::Empty)?;
         Ok(ResultType::IntResult(*max))
     }
 
-    fn part2(&self, lines: &str) -> Result<ResultType> {
+    fn part2(&self, lines: &str) -> anyhow::Result<ResultType> {
         let vector = Day::parse(lines)?;
         let sum = vector.iter().sorted_by(|a, b| Ord::cmp(b, a)).take(3).sum();
         Ok(ResultType::IntResult(sum))

src/days/day02/mod.rs

@@ -1,7 +1,6 @@
 use std::cmp::Ordering;
 
 use super::template::{DayTrait, ResultType};
-use anyhow::Result;
 use thiserror::Error;
 
 const DAY_NUMBER: usize = 2;
@@ -13,11 +12,11 @@ impl DayTrait for Day {
         DAY_NUMBER
     }
 
-    fn part1(&self, lines: &str) -> Result<ResultType> {
+    fn part1(&self, lines: &str) -> anyhow::Result<ResultType> {
         let sum = lines
             .split("\n")
             .map(RPS::parse_line)
-            .collect::<Result<Vec<_>>>()?
+            .collect::<Result<Vec<_>, _>>()?
             .into_iter()
             .map(|(first, second)| second.asses_pair(&first))
             .sum();
@@ -25,11 +24,11 @@ impl DayTrait for Day {
         Ok(ResultType::IntResult(sum))
     }
 
-    fn part2(&self, lines: &str) -> Result<ResultType> {
+    fn part2(&self, lines: &str) -> anyhow::Result<ResultType> {
         let sum = lines
             .split("\n")
             .map(Strategy::parse_line)
-            .collect::<Result<Vec<_>>>()?
+            .collect::<Result<Vec<_>, _>>()?
             .into_iter()
             .map(|(first, second)| second.fullfill(&first).asses_pair(&first))
             .sum();
@@ -55,7 +54,7 @@ enum RPS {
 }
 
 impl RPS {
-    pub fn parse_line(line: &str) -> Result<(Self, Self)> {
+    pub fn parse_line(line: &str) -> Result<(Self, Self), RPSError> {
         let mut parts = line.split(" ");
         let (Some(first), Some(second)) = (parts.next(), parts.next()) else {
             Err(RPSError::IllegalLine(line.to_owned()))?
@@ -119,7 +118,7 @@ enum Strategy {
 }
 
 impl Strategy {
-    pub fn parse_line(line: &str) -> Result<(RPS, Self)> {
+    pub fn parse_line(line: &str) -> Result<(RPS, Self), RPSError> {
         let mut parts = line.split(" ");
         let (Some(first), Some(second)) = (parts.next(), parts.next()) else {
             Err(RPSError::IllegalLine(line.to_owned()))?

src/days/day03/mod.rs

@@ -0,0 +1,144 @@
+use itertools::Itertools;
+use thiserror::Error;
+
+use super::template::{DayTrait, ResultType};
+
+const DAY_NUMBER: usize = 3;
+
+pub struct Day;
+
+impl DayTrait for Day {
+    fn get_day_number(&self) -> usize {
+        DAY_NUMBER
+    }
+
+    fn part1(&self, lines: &str) -> anyhow::Result<ResultType> {
+        let sum = lines
+            .split('\n')
+            .map(|rucksack| find_double(rucksack).and_then(priority))
+            .collect::<Result<Vec<_>, _>>()?
+            .iter()
+            .sum();
+        Ok(ResultType::IntResult(sum))
+    }
+
+    fn part2(&self, lines: &str) -> anyhow::Result<ResultType> {
+        let sum = lines
+            .split('\n')
+            .chunks(3)
+            .into_iter()
+            .map(|chunk| find_badge(&chunk.collect::<Vec<_>>()).and_then(priority))
+            .collect::<Result<Vec<_>, _>>()?
+            .iter()
+            .sum();
+        Ok(ResultType::IntResult(sum))
+    }
+}
+
+#[derive(Debug, Error)]
+enum RucksackError {
+    #[error("No double item found")]
+    NoDoubleFound,
+
+    #[error("Not a valid char: {0}")]
+    InvalidChar(char),
+
+    #[error("Need at least two elves for common item")]
+    NeedAtLeastTwo,
+
+    #[error("No common badge was found")]
+    NoBadgeFound,
+}
+
+fn priority(c: char) -> Result<i64, RucksackError> {
+    match c {
+        'a'..='z' => Ok(c as i64 - 'a' as i64 + 1),
+        'A'..='Z' => Ok(c as i64 - 'A' as i64 + 27),
+        _ => Err(RucksackError::InvalidChar(c)),
+    }
+}
+
+fn find_double(content: &str) -> Result<char, RucksackError> {
+    let length = content.len() / 2;
+    let part1 = &content[..length];
+    let part2 = &content[length..];
+
+    for c in part1.chars() {
+        if part2.contains(c) {
+            return Ok(c);
+        }
+    }
+
+    Err(RucksackError::NoDoubleFound)?
+}
+
+fn find_badge<'a>(elves: &[&str]) -> Result<char, RucksackError> {
+    if elves.len() < 2 {
+        return Err(RucksackError::NeedAtLeastTwo);
+    };
+    for c in elves[0].chars() {
+        let mut found = true;
+        for other in &elves[1..] {
+            if !other.contains(c) {
+                found = false;
+            }
+        }
+        if found {
+            return Ok(c);
+        }
+    }
+    Err(RucksackError::NoBadgeFound)
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+    use crate::common::file::read_data;
+    use anyhow::Result;
+
+    #[test]
+    fn test_rucksack() -> Result<(), RucksackError> {
+        let input = "vJrwpWtwJgWrhcsFMMfFFhFp";
+        let expected = 16;
+        let result = find_double(input).and_then(priority)?;
+        assert_eq!(result, expected);
+
+        Ok(())
+    }
+
+    #[test]
+    fn test_part1() -> Result<()> {
+        let day = Day {};
+        let lines = read_data(day.get_day_number(), "example01.txt")?;
+        let expected = ResultType::IntResult(157);
+        let result = day.part1(&lines)?;
+        assert_eq!(result, expected);
+
+        Ok(())
+    }
+
+    #[test]
+    fn test_find_badge() -> Result<(), RucksackError> {
+        let input = vec![
+            "vJrwpWtwJgWrhcsFMMfFFhFp",
+            "jqHRNqRjqzjGDLGLrsFMfFZSrLrFZsSL",
+            "PmmdzqPrVvPwwTWBwg",
+        ];
+        let expected = 18;
+        let result = find_badge(&input).and_then(priority)?;
+        assert_eq!(result, expected);
+
+        Ok(())
+    }
+
+    #[test]
+    fn test_part2() -> Result<()> {
+        let day = Day {};
+        let lines = read_data(day.get_day_number(), "example01.txt")?;
+        let expected = ResultType::IntResult(70);
+        let result = day.part2(&lines)?;
+        assert_eq!(result, expected);
+
+        Ok(())
+    }
+}

src/days/day__/mod.rs

@@ -1,5 +1,3 @@
-use anyhow::Result;
-
 use super::template::{DayTrait, ResultType};
 
 const DAY_NUMBER: usize = 0;
@@ -11,11 +9,11 @@ impl DayTrait for Day {
         DAY_NUMBER
     }
 
-    fn part1(&self, _lines: &str) -> Result<ResultType> {
+    fn part1(&self, _lines: &str) -> anyhow::Result<ResultType> {
         Ok(ResultType::NoResult)
     }
 
-    fn part2(&self, _lines: &str) -> Result<ResultType> {
+    fn part2(&self, _lines: &str) -> anyhow::Result<ResultType> {
         Ok(ResultType::NoResult)
     }
 }

src/days/mod.rs

@@ -1,5 +1,6 @@
 mod day01;
 mod day02;
+mod day03;
 mod template;
 
 pub use template::DayTrait;
@@ -9,12 +10,13 @@ pub mod day_provider {
     use super::*;
     use thiserror::Error;
 
-    const MAX_DAY: usize = 2;
+    const MAX_DAY: usize = 3;
 
     pub fn get_day(day_num: usize) -> Result<Box<dyn DayTrait>, ProviderError> {
         match day_num {
             1 => Ok(Box::new(day01::Day)),
             2 => Ok(Box::new(day02::Day)),
+            3 => Ok(Box::new(day03::Day)),
             _ => Err(ProviderError::InvalidNumber(day_num)),
         }
     }