Cleanup for 2022 days 22 through 25: Turned into a lib and introduced parse errors

2022/day22-monkey_map/src/lib.rs

@@ -1,4 +1,19 @@
-use std::fs;
+use core::fmt::Display;
+
+#[derive(Debug, PartialEq, Eq)]
+pub enum ParseError<'a> {
+    InputMalformed(&'a str),
+    InvalidChar(char),
+}
+
+impl Display for ParseError<'_> {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Self::InputMalformed(v) => write!(f, "Unable to split Input into Map and Instructions. Input should consist of 2 parts, separated by an empty line:\n{v}"),
+            Self::InvalidChar(c) => write!(f, "Invalid Character {c} encountered"),
+        }
+    }
+}
 
 #[derive(Clone, Copy, Debug, PartialEq)]
 enum Direction { 
@@ -14,7 +29,6 @@ enum Wrapping { Flat, Cube(isize) }
 #[derive(PartialEq)]
 enum Walkability { Free, Obstructed, Void }
 
-//#[derive(Debug)]
 enum Instruction { Go(usize), Turn(char) }
 
 #[derive(Clone, Copy)]
@@ -193,23 +207,23 @@ impl Position {
     }
 }
 
-fn parse_map(string: &str) -> Vec<Vec<Walkability>> {
+fn try_parse_map(string: &str) -> Result<Vec<Vec<Walkability>>, ParseError> {
     string.lines()
         .map(|line| line.chars()
                 .map(|c| match c {
-                        ' ' => Walkability::Void,
-                        '.' => Walkability::Free,
-                        '#' => Walkability::Obstructed,
-                        _ => panic!("Unexpected Map Item: {c}"),
+                        ' ' => Ok(Walkability::Void),
+                        '.' => Ok(Walkability::Free),
+                        '#' => Ok(Walkability::Obstructed),
+                        _ => Err(ParseError::InvalidChar(c)),
                     })
                 .collect())
-        .collect()
+        .collect::<Result<Vec<_>, _>>()
 }
 
-fn parse_instructions(line: &str) -> Vec<Instruction> {
+fn try_parse_instructions(line: &str) -> Result<Vec<Instruction>, ParseError> {
     let mut instructions = Vec::new();
     let mut distance = 0_usize;
-    line.chars().for_each(|c| {
+    for c in line.chars() {
         if let Some(d) = c.to_digit(10) {
             distance *= 10;
             distance += d as usize;
@@ -219,20 +233,22 @@ fn parse_instructions(line: &str) -> Vec<Instruction> {
                 distance = 0;
             }
             instructions.push(Instruction::Turn(c));
+        } else if c == '\n' {
+            continue;
+        } else {
+            return Err(ParseError::InvalidChar(c));
+        }
     }
-    });
     if distance > 0 {
         instructions.push(Instruction::Go(distance));
     }
-    instructions
+    Ok(instructions)
 }
 
-fn read_file(path: &str) -> (Vec<Vec<Walkability>>, Vec<Instruction>) {
-    let components = fs::read_to_string(path)
-        .expect("File not Found");
-    let (map_str, instructions_str) = components.split_once("\n\n").unwrap();
-    (parse_map(map_str), parse_instructions(instructions_str))
-}
+// fn read_file(input: &str) -> (Vec<Vec<Walkability>>, Vec<Instruction>) {
+//     let (map_str, instructions_str) = components.split_once("\n\n").unwrap();
+//     (parse_map(map_str), parse_instructions(instructions_str))
+// }
 
 fn get_password(map: &[Vec<Walkability>], instructions: &[Instruction], wrapping: Wrapping) -> usize {
     let mut position = Position {
@@ -250,29 +266,38 @@ fn get_password(map: &[Vec<Walkability>], instructions: &[Instruction], wrapping
     (position.coordinate.row + 1) * 1000 + (position.coordinate.col + 1) * 4 + position.facing as usize
 }
 
-fn main() {
-    let (map, instructions) = read_file("input");
-
-    println!("Flat Map ended up at Password {}", get_password(&map, &instructions, Wrapping::Flat));
+pub fn run(input: &str) -> Result<(usize, usize), ParseError> {
+    let (map, instructions) = input.split_once("\n\n").ok_or(ParseError::InputMalformed(input))?;
+    let map = try_parse_map(map)?;
+    let instructions = try_parse_instructions(instructions)?;
+    let first = get_password(&map, &instructions, Wrapping::Flat);
     let side_length = (map.iter().map(|i| i.iter().filter(|&w| *w != Walkability::Void).count()).sum::<usize>() as f64 / 6.0).sqrt() as isize;
-    println!("Cube Map ended up at Password {}.", get_password(&map, &instructions, Wrapping::Cube(side_length)));
+    let second = get_password(&map, &instructions, Wrapping::Cube(side_length));
+    Ok((first, second))
 }
 
-#[test]
-fn sample_input() {
-    let (map, instructions) = read_file("tests/sample_input");
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::fs::read_to_string;
 
+    fn read_file(name: &str) -> String {
+        read_to_string(name).expect(&format!("Unable to read file: {name}")[..])
+    }
+
+    #[test]
+    fn test_sample() {
+        let sample_input = read_file("tests/sample_input");
+        let (map, instructions) = &sample_input[..].split_once("\n\n").unwrap();
+        let map = try_parse_map(map).unwrap();
+        let instructions = try_parse_instructions(instructions).unwrap();
         assert_eq!(get_password(&map, &instructions, Wrapping::Flat), 6032);
-    let side_length = (map.iter().map(|i| i.iter().filter(|&w| *w != Walkability::Void).count()).sum::<usize>() as f64 / 6.0).sqrt() as isize;
-    // Part 2 does not work for the sample input, sice it is shaped differently.
-    assert_eq!(side_length, 4);
-}
+        assert_eq!((map.iter().map(|i| i.iter().filter(|&w| *w != Walkability::Void).count()).sum::<usize>() as f64 / 6.0).sqrt() as isize, 4);
+    }
 
-#[test]
-fn challenge_input() {
-    let (map, instructions) = read_file("tests/input");
-
-    assert_eq!(get_password(&map, &instructions, Wrapping::Flat), 58248);
-    let side_length = (map.iter().map(|i| i.iter().filter(|&w| *w != Walkability::Void).count()).sum::<usize>() as f64 / 6.0).sqrt() as isize;
-    assert_eq!(get_password(&map, &instructions, Wrapping::Cube(side_length)), 179091);
+    #[test]
+    fn test_challenge() {
+        let challenge_input = read_file("tests/challenge_input");
+        assert_eq!(run(&challenge_input), Ok((58248, 179091)));
+    }
 }

2022/day23-unstable_diffusion/src/lib.rs

@@ -1,4 +1,18 @@
-use std::{fs, isize, collections::HashMap};
+use core::fmt::Display;
+use std::collections::HashMap;
+
+#[derive(Debug, PartialEq, Eq)]
+pub enum ParseError {
+    UnexpectedMapFeature(char, usize, usize),
+}
+
+impl Display for ParseError {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Self::UnexpectedMapFeature(c, x, y) => write!(f, "Trying to parse unexpected map feature {c} at x={x}, y={y}"),
+        }
+    }
+}
 
 #[derive(Clone, Copy, PartialEq)]
 enum Tile { Free, Elf, ProposedOnce, ProposedMultiple }
@@ -105,22 +119,6 @@ impl Elf {
     }
 }
 
-fn read_file(path: &str) -> HashMap<(isize, isize), Tile> {
-    fs::read_to_string(path)
-        .expect("File not Found")
-        .lines()
-        .enumerate()
-        .flat_map(|(y, l)| l.chars()
-            .enumerate()
-            .map(move |(x, c)| ((x as isize, y as isize), match c {
-                '.' => Tile::Free,
-                '#' => Tile::Elf,
-                _ => panic!("Unexpected Map Feature: {c} at {x}, {y}"),
-            })))
-        .collect()
-}
-
-
 fn get_free_tiles(elfs: &mut [Elf], grid: &mut HashMap<(isize, isize), Tile>, rounds: usize) -> usize {
     for round in 0..rounds {
         elfs.iter_mut().for_each(|elf| *elf = elf.consider(round, grid));
@@ -142,7 +140,7 @@ fn get_free_tiles(elfs: &mut [Elf], grid: &mut HashMap<(isize, isize), Tile>, ro
 fn get_last_round(elfs: &mut [Elf], grid: &mut HashMap<(isize, isize), Tile>, starting_round: usize) -> usize {
     for round in starting_round.. {
         elfs.iter_mut().for_each(|elf| *elf = elf.consider(round, grid));
-        if !elfs.iter().any(|elf| elf.considered != None) {
+        if !elfs.iter().any(|elf| elf.considered.is_some()) {
             return round + 1;
         }
         elfs.iter_mut().for_each(|elf| *elf = elf.reposition(grid));
@@ -150,40 +148,45 @@ fn get_last_round(elfs: &mut [Elf], grid: &mut HashMap<(isize, isize), Tile>, st
     unreachable!("The loop always returns");
 }
 
-fn main() {
-    let mut grid = read_file("input");
-
+pub fn run(input: &str) -> Result<(usize, usize), ParseError> {
+    let mut grid: HashMap<_, _> = input.lines()
+        .enumerate()
+        .flat_map(|(y, l)| l.chars()
+            .enumerate()
+            .map(move |(x, c)| match c {
+                '.' => Ok(((x as isize, y as isize), Tile::Free)),
+                '#' => Ok(((x as isize, y as isize), Tile::Elf)),
+                _ => Err(ParseError::UnexpectedMapFeature(c, x, y)),
+            }))
+        .collect::<Result<HashMap<_, _>, _>>()?;
     let mut elfs: Vec<Elf> = grid.iter()
         .filter(|((_, _), &tile)| tile==Tile::Elf)
         .map(|((x, y), _)| Elf { x: *x, y: *y, considered: None })
         .collect();
 
-    println!("After 10 Rounds, {} tiles are free.", get_free_tiles(&mut elfs, &mut grid, 10));
-    println!("No more movement after round {}.", get_last_round(&mut elfs, &mut grid, 10));
+    let first = get_free_tiles(&mut elfs, &mut grid, 10);
+    let second = get_last_round(&mut elfs, &mut grid, 10);
+    Ok((first, second))
 }
 
-#[test]
-fn sample_input() {
-    let mut grid = read_file("tests/sample_input");
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::fs::read_to_string;
 
-    let mut elfs: Vec<Elf> = grid.iter()
-        .filter(|((_, _), &tile)| tile==Tile::Elf)
-        .map(|((x, y), _)| Elf { x: *x, y: *y, considered: None })
-        .collect();
+    fn read_file(name: &str) -> String {
+        read_to_string(name).expect(&format!("Unable to read file: {name}")[..]).trim().to_string()
+    }
 
-    assert_eq!(get_free_tiles(&mut elfs, &mut grid, 10), 110);
-    assert_eq!(get_last_round(&mut elfs, &mut grid, 10), 20);
-}
-
-#[test]
-fn challenge_input() {
-    let mut grid = read_file("tests/input");
-
-    let mut elfs: Vec<Elf> = grid.iter()
-        .filter(|((_, _), &tile)| tile==Tile::Elf)
-        .map(|((x, y), _)| Elf { x: *x, y: *y, considered: None })
-        .collect();
-
-    assert_eq!(get_free_tiles(&mut elfs, &mut grid, 10), 4068);
-    assert_eq!(get_last_round(&mut elfs, &mut grid, 10), 968);
+    #[test]
+    fn test_sample() {
+        let sample_input = read_file("tests/sample_input");
+        assert_eq!(run(&sample_input), Ok((110, 20)));
+    }
+
+    #[test]
+    fn test_challenge() {
+        let challenge_input = read_file("tests/challenge_input");
+        assert_eq!(run(&challenge_input), Ok((4068, 968)));
+    }
 }

2022/day24-blizzard_basin/src/lib.rs

@@ -1,4 +1,19 @@
-use std::fs;
+use core::fmt::Display;
+
+#[derive(Debug, PartialEq, Eq)]
+pub enum ParseError {
+    StartNotFound,
+    UnexpectedChar(char)
+}
+
+impl Display for ParseError {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Self::StartNotFound => write!(f, "Unable to find a starting blizzard in row 0"),
+            Self::UnexpectedChar(c) => write!(f, "Trying to parse unexpected character {c} into map"),
+        }
+    }
+}
 
 #[derive(PartialEq)]
 enum Direction { Up, Down, Left, Right }
@@ -65,16 +80,12 @@ impl Blizard {
     }
 }
 
-fn read_file(path: &str) -> (Vec<Vec<Tile>>, Vec<Blizard>) {
+fn try_parse(input: &str) -> Result<(Vec<Vec<Tile>>, Vec<Blizard>), ParseError> {
     let mut map = Vec::new();
     let mut blizzards = Vec::new();
-    fs::read_to_string(path)
-        .expect("File not Found")
-        .lines()
-        .enumerate()
-        .for_each(|(y, line)| {
+    for (y, line) in input.lines().enumerate() {
             let mut this_line = Vec::new();
-            line.chars().enumerate().for_each(|(x, c)| {
+            for (x, c) in line.chars().enumerate() {
                 match &c {
                     '.' => this_line.push(Tile::Blizards(0)),
                     '#' => this_line.push(Tile::Wall),
@@ -94,12 +105,12 @@ fn read_file(path: &str) -> (Vec<Vec<Tile>>, Vec<Blizard>) {
                             this_line.push(Tile::Blizards(1));
                             blizzards.push(Blizard { x, y, direction: Direction::Down });
                         },
-                    _ => panic!("Unexpected Map Character: {c}"),
+                    c => return Err(ParseError::UnexpectedChar(*c)),
+                }
             }
-            });
             map.push(this_line);
-        });
-    (map, blizzards)
+        }
+    Ok((map, blizzards))
 }
 
 fn get_neighbours((x, y): (usize, usize), max_x: usize, max_y: usize) -> Vec<(usize, usize)> {
@@ -149,37 +160,36 @@ fn get_rounds_from_to(start: (usize, usize), destination: (usize, usize), map: &
     rounds
 }
 
-fn main() {
-    let (mut map, mut blizzards) = read_file("input");
-    let start = (map[0].iter().position(|tile| *tile == Tile::Blizards(0)).unwrap(), 0);
+pub fn run(input: &str) -> Result<(usize, usize), ParseError> {
+    let (mut map, mut blizzards) = try_parse(input)?;
+    let start = (map[0].iter().position(|tile| *tile == Tile::Blizards(0)).ok_or(ParseError::StartNotFound)?, 0);
     let destination = (map[map.len()-1].iter().position(|tile| *tile == Tile::Blizards(0)).unwrap(), map.len()-1);
 
-    let mut rounds = get_rounds_from_to(start, destination, &mut map, &mut blizzards);
-    println!("Reached desitnation after {} rounds.", rounds);
-    rounds += get_rounds_from_to(destination, start, &mut map, &mut blizzards);
-    println!("Reached start again after {} rounds.", rounds);
-    rounds += get_rounds_from_to(start, destination, &mut map, &mut blizzards);
-    println!("Reached desitnation after {} rounds.", rounds);
+    let mut second = get_rounds_from_to(start, destination, &mut map, &mut blizzards);
+    let first = second;
+    second += get_rounds_from_to(destination, start, &mut map, &mut blizzards);
+    second += get_rounds_from_to(start, destination, &mut map, &mut blizzards);
+    Ok((first, second))
 }
 
-#[test]
-fn sample_input() {
-    let (mut map, mut blizzards) = read_file("tests/sample_input");
-    let start = (map[0].iter().position(|tile| *tile == Tile::Blizards(0)).unwrap(), 0);
-    let destination = (map[map.len()-1].iter().position(|tile| *tile == Tile::Blizards(0)).unwrap(), map.len()-1);
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::fs::read_to_string;
 
-    assert_eq!(get_rounds_from_to(start, destination, &mut map, &mut blizzards), 18);
-    assert_eq!(get_rounds_from_to(destination, start, &mut map, &mut blizzards), 23);
-    assert_eq!(get_rounds_from_to(start, destination, &mut map, &mut blizzards), 13);
-}
-
-#[test]
-fn challenge_input() {
-    let (mut map, mut blizzards) = read_file("tests/input");
-    let start = (map[0].iter().position(|tile| *tile == Tile::Blizards(0)).unwrap(), 0);
-    let destination = (map[map.len()-1].iter().position(|tile| *tile == Tile::Blizards(0)).unwrap(), map.len()-1);
-
-    assert_eq!(get_rounds_from_to(start, destination, &mut map, &mut blizzards), 277);
-    assert_eq!(get_rounds_from_to(destination, start, &mut map, &mut blizzards), 305);
-    assert_eq!(get_rounds_from_to(start, destination, &mut map, &mut blizzards), 295);
+    fn read_file(name: &str) -> String {
+        read_to_string(name).expect(&format!("Unable to read file: {name}")[..]).trim().to_string()
+    }
+
+    #[test]
+    fn test_sample() {
+        let sample_input = read_file("tests/sample_input");
+        assert_eq!(run(&sample_input), Ok((18, 54)));
+    }
+
+    #[test]
+    fn test_challenge() {
+        let challenge_input = read_file("tests/challenge_input");
+        assert_eq!(run(&challenge_input), Ok((277, 877)));
+    }
 }

2022/day25-full_of_hot_air/src/lib.rs

@@ -0,0 +1,126 @@
+use core::fmt::Display;
+
+#[derive(Debug, PartialEq, Eq)]
+pub enum ParseError {
+    InvalidChar(char),
+}
+
+impl Display for ParseError {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Self::InvalidChar(c) => write!(f, "Unexpected character: {c} should not be part of a SNAFU number."),
+        }
+    }
+}
+
+#[derive(Clone, Copy)]
+enum SnafuDigit { Zero, One, Two, Minus, DoubleMinus }
+struct Snafu(Vec<SnafuDigit>);
+
+impl TryFrom<&str> for Snafu {
+    type Error = ParseError;
+
+    fn try_from(value: &str) -> Result<Self, Self::Error> {
+        Ok(Self(value.chars().map(|c| match c {
+            '0' => Ok(SnafuDigit::Zero),
+            '1' => Ok(SnafuDigit::One),
+            '2' => Ok(SnafuDigit::Two),
+            '-' => Ok(SnafuDigit::Minus),
+            '=' => Ok(SnafuDigit::DoubleMinus),
+            c => Err(Self::Error::InvalidChar(c)),
+        }).collect::<Result<Vec<_>, _>>()?))
+    }
+}
+
+impl From<SnafuDigit> for char {
+    fn from(value: SnafuDigit) -> Self {
+        match value {
+            SnafuDigit::Zero => '0',
+            SnafuDigit::One => '1',
+            SnafuDigit::Two => '2',
+            SnafuDigit::Minus => '-',
+            SnafuDigit::DoubleMinus => '=',
+        }
+    }
+}
+
+impl Display for Snafu {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{}", self.0.iter().cloned().map(char::from).collect::<String>())
+    }
+}
+
+impl From<Snafu> for isize {
+    fn from(value: Snafu) -> Self {
+        let mut res = 0;
+
+        for d in value.0 {
+            res *= 5;
+            match d {
+                SnafuDigit::Zero => (),
+                SnafuDigit::One => res += 1,
+                SnafuDigit::Two => res += 2,
+                SnafuDigit::Minus => res -= 1,
+                SnafuDigit::DoubleMinus => res -= 2,
+            }
+        }
+
+        res
+    }
+}
+
+impl From<isize> for Snafu {
+    fn from(value: isize) -> Self {
+        let mut digits = Vec::new();
+        let mut value = value;
+
+        while value != 0 {
+            let digit = value % 5;
+            match digit {
+                0 => digits.push(SnafuDigit::Zero),
+                1 => digits.push(SnafuDigit::One),
+                2 => digits.push(SnafuDigit::Two),
+                3 => digits.push(SnafuDigit::DoubleMinus),
+                4 => digits.push(SnafuDigit::Minus),
+                _ => unreachable!("value%5 can only ever be one of the values above"),
+            }
+            if digit > 2 {
+                value += 2;
+            }
+            value /= 5;
+        }
+        digits.reverse();
+
+        Self(digits)
+    }
+}
+
+pub fn run(input: &str) -> Result<String, ParseError> {
+    let total = input.lines()
+        .map(|s| Snafu::try_from(s).map(isize::from))
+        .sum::<Result<isize, _>>()?;
+
+    Ok(format!("{}", Snafu::from(total)))
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::fs::read_to_string;
+
+    fn read_file(name: &str) -> String {
+        read_to_string(name).expect(&format!("Unable to read file: {name}")[..]).trim().to_string()
+    }
+
+    #[test]
+    fn test_sample() {
+        let sample_input = read_file("tests/sample_input");
+        assert_eq!(run(&sample_input), Ok("2=-1=0".to_string()));
+    }
+
+    #[test]
+    fn test_challenge() {
+        let challenge_input = read_file("tests/challenge_input");
+        assert_eq!(run(&challenge_input), Ok("2-0=11=-0-2-1==1=-22".to_string()));
+    }
+}

2022/day25-full_of_hot_air/src/main.rs

@@ -1,75 +0,0 @@
-use std::fs;
-
-fn from_snafu(snafu_num: &str) -> isize {
-    let mut number = 0;
-
-    snafu_num.chars().for_each(|c| {
-        number *= 5;
-        match &c {
-            '0' | '1' | '2' => number += (c as u8 - b'0') as isize,
-            '-' => number -= 1,
-            '=' => number -= 2,
-            _ => panic!("Unexpected character: {c} should not be part of a SNAFU number."),
-        }
-    });
-    number
-}
-
-fn to_snafu(number: isize) -> String {
-    let mut snafu_num = String::new();
-
-    let mut temp = number;
-    while temp != 0 {
-        let digit = ( temp % 5) as u8;
-        match digit {
-            0 | 1 | 2 => snafu_num.push((digit + b'0') as char),
-            3 => {
-                    snafu_num.push('=');
-                    temp += 2;
-                },
-            _ => {
-                    snafu_num.push('-');
-                    temp += 2;
-                },
-        }
-        temp /= 5;
-    }
-
-    snafu_num.chars().rev().collect()
-}
-
-fn read_file(path: &str) -> Vec<String> {
-    fs::read_to_string(path)
-        .expect("File not Found")
-        .lines()
-        .map(String::from)
-        .collect()
-}
-
-fn main() {
-    let list = read_file("input");
-    
-    let total = list.iter()
-        .map(|snafu_num| from_snafu(snafu_num))
-        .sum::<isize>();
-
-    println!("The total Fuel Usage is {total}, which is {} in SNAFU numbers.", to_snafu(total));
-}
-
-#[test]
-fn sample_input() {
-    let list = read_file("tests/sample_input");
-    let total = list.iter().map(|s| from_snafu(s)).sum::<isize>();
-
-    assert_eq!(total, 4890);
-    assert_eq!(to_snafu(total), "2=-1=0");
-}
-
-#[test]
-fn challenge_input() {
-    let list = read_file("tests/input");
-    let total = list.iter().map(|s| from_snafu(s)).sum::<isize>();
-
-    assert_eq!(total, 34061028947237);
-    assert_eq!(to_snafu(total), "2-0=11=-0-2-1==1=-22");
-}