Add solution for 2022 day 12

2022/Cargo.lock

@@ -55,12 +55,48 @@ dependencies = [
  "itertools",
 ]
 
+[[package]]
+name = "aoc-2022-12"
+version = "0.1.0"
+dependencies = [
+ "itertools",
+ "petgraph",
+]
+
+[[package]]
+name = "autocfg"
+version = "1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d468802bab17cbc0cc575e9b053f41e72aa36bfa6b7f55e3529ffa43161b97fa"
+
 [[package]]
 name = "either"
 version = "1.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "90e5c1c8368803113bf0c9584fc495a58b86dc8a29edbf8fe877d21d9507e797"
 
+[[package]]
+name = "fixedbitset"
+version = "0.4.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0ce7134b9999ecaf8bcd65542e436736ef32ddca1b3e06094cb6ec5755203b80"
+
+[[package]]
+name = "hashbrown"
+version = "0.12.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8a9ee70c43aaf417c914396645a0fa852624801b24ebb7ae78fe8272889ac888"
+
+[[package]]
+name = "indexmap"
+version = "1.9.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1885e79c1fc4b10f0e172c475f458b7f7b93061064d98c3293e98c5ba0c8b399"
+dependencies = [
+ "autocfg",
+ "hashbrown",
+]
+
 [[package]]
 name = "itertools"
 version = "0.10.5"
@@ -69,3 +105,13 @@ checksum = "b0fd2260e829bddf4cb6ea802289de2f86d6a7a690192fbe91b3f46e0f2c8473"
 dependencies = [
  "either",
 ]
+
+[[package]]
+name = "petgraph"
+version = "0.6.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e6d5014253a1331579ce62aa67443b4a658c5e7dd03d4bc6d302b94474888143"
+dependencies = [
+ "fixedbitset",
+ "indexmap",
+]

2022/Cargo.toml

@@ -11,6 +11,7 @@ members = [
     "./day-09",
     "./day-10",
     "./day-11",
+    "./day-12",
 ]
 
 

2022/README.md

@@ -15,7 +15,7 @@
 | [09] |   ✓    |   ✓    | [Rust]   |
 | [10] |   ✓    |   ✓    | [Rust]   |
 | [11] |   ✓    |        | [Rust]   |
-| [12] |        |        |          |
+| [12] |   ✓    |   ✓    | [Rust]   |
 | [13] |        |        |          |
 | [14] |        |        |          |
 | [15] |        |        |          |

2022/day-12/Cargo.toml

@@ -0,0 +1,14 @@
+[package]
+name = "aoc-2022-12"
+version = "0.1.0"
+edition = "2021"
+
+
+[lib]
+test = false
+doctest = false
+
+
+[dependencies]
+petgraph = "0.6.2"
+itertools = "0.10"

2022/day-12/Justfile

@@ -0,0 +1,5 @@
+@part PART INPUT_FILE="inputs/puzzle.txt":
+    cargo --quiet run --bin part_{{PART}} -- {{INPUT_FILE}}
+
+clean:
+    cargo clean

2022/day-12/inputs/puzzle.txt

@@ -0,0 +1,41 @@
+abcccccccccaaaaaaaaaaccccccccccccaaaaaaaaccaaccccccccccccccccccccccccccccccccccccccccccccaaaaaa
+abccccccccccaaaaaaaaaccccccccccccaaaaaaaaaaaacccccccccccaacccacccccccccccccccccccccccccccaaaaaa
+abcccccccccccaaaaaaacccccccccccccaaaaaaaaaaaaaacccccccccaaacaacccccccccaaaccccccccccccccccaaaaa
+abccccccccccaaaaaaccccccccccccccaaaaaaaaaaaaaaaccccccccccaaaaaccccccccccaaacccccccccccccccccaaa
+abccccccccccaaaaaaaccccccccccccaaaaaaaaaaaaaacccccccccccaaaaaacccccccccaaaacccccccccccccccccaac
+abaaccaaccccaaccaaaccccccccaaaaaaaaaaaaaaacaaccccccccccaaaaaaaacccccccccaaalcccccccccccccccaaac
+abaaaaaacccccccccaaccccccccaaaaaacccaaaacccaaccccccccccaaaaaaaaccccccccalllllllcccccccccccccccc
+abaaaaaacccccccaaacccccccccaaaaccccccaaaccccaaaaacccccccccaacccccccaaaakllllllllcccccccaacccccc
+abaaaaaacccccccaaaacccccccccaacccccccaaaccccaaaaacccccccccaacccccccaakkklllpllllccccacaaacccccc
+abaaaaaaaccccccaaaaccccaaccccccccccccccccccaaaaaaccccccccccccccccccckkkkpppppplllcccaaaaaaacccc
+abaaaaaaacaaaccaaaaccaaaaaaccccccccccccccccaaaaaacccccccaaaccccckkkkkkkpppppppplllcddaaaaaacccc
+abcaaaacccaacccccccccaaaaaacccccaaaccccccccaaaaaacccccccaaaaccjkkkkkkkpppppuppplmmdddddaaaccccc
+abccaaaaaaaaaccccccccaaaaaaccccaaaaaacccccccaaacccccccccaaaajjjkkkkkrpppuuuuupppmmmdddddacccccc
+abccccaaaaaaaacccccccaaaaacccccaaaaaacccccccccccccccccccaaacjjjjrrrrrrppuuuuupqqmmmmmddddaccccc
+abccccaaaaaaaaacccccccaaaacccccaaaaaaccccccccccccccccccccccjjjrrrrrrrrpuuuxuvvqqqmmmmmddddccccc
+abccccaaaaaaaaacccccccccccccccccaaaaaccccaacccaccccccccaaccjjjrrrruuuuuuuxxyvvqqqqqmmmmmdddcccc
+abccccaaaaaaaacccccccccaaaccccccaacaaccccaaacaacccaaacaaaccjjjrrrtuuuuuuuxxyvvvqqqqqmmmmdddcccc
+abccaaaaaaaacccccccccccaaaaaccccccccccccccaaaaacccaaaaaaaccjjjrrttttxxxxxxyyvvvvvqqqqmmmmdeeccc
+abccaaaccaaaccccccccaacaaaaacccccccccccccaaaaaacccaaaaaacccjjjrrtttxxxxxxxyyvvvvvvvqqqmmmeeeccc
+abaaaaaaaaaacccaaaccaaaaaaaaaaaccaaaccccaaaaaaaacccaaaaaaaajjjqqrttxxxxxxxyyyyyyvvvqqqnnneeeccc
+SbaaaaaaaaccccaaaaccaaaaaaaaaaaaaaaaacccaaaaaaaaccaaaaaaaaacjjjqqtttxxxxEzzyyyyvvvvqqqnnneeeccc
+abcaaaaaacccccaaaaccccaaaaaaaccaaaaaaccccccaaccccaaaaaaaaaaciiiqqqtttxxxyyyyyyvvvvrrrnnneeecccc
+abcaaaaaacccccaaaacccaaaaaaaaccaaaaaaccccccaaccccaaacaaacccciiiqqqqttxxyyyyyywvvvrrrnnneeeecccc
+abcaaaaaaccccccccccccaaaaaaaaacaaaaacccccccccccccccccaaaccccciiiqqtttxxyyyyyywwrrrrnnnneeeccccc
+abcaaacaacccccaacccccaaaaaaaaacaaaaacccccccccccccccccaaaccccciiiqqttxxxywwyyywwrrrnnnneeecccccc
+abccccccccaaacaaccccccccccacccccccccccccccccccccccccccccccccciiqqqttxxwwwwwwywwrrrnnneeeccccccc
+abccaacccccaaaaaccccccccccccccccccccccccccccccccccccccccaacaaiiqqqttwwwwsswwwwwrrrnnfffeccccccc
+abaaaaccccccaaaaaacccccccccccccccccccccccccccccaaaccccccaaaaaiiqqqttssssssswwwwrrronfffaccccccc
+abaaaaaacccaaaaaaacccccccccccccccccccccccccccaaaaaacccccaaaaaiiqqqssssssssssswrrrooofffaaaacccc
+abaaaaaaccaaaaaacccccccccccccccccccccccccccccaaaaaacccccaaaaaiiqqqppssspppssssrrrooofffaaaacccc
+abaaaaaaccaacaaacccccccccccccccccccccccccccccaaaaaacccccaaaaaiihpppppppppppossrrooofffaaaaacccc
+abaaaaccccccccaacccccccccccccccccccccccccccccaaaaaccccccccaaahhhhppppppppppoooooooofffaaaaccccc
+abaaaaccccccccccaacccccccccccccccccaaacccccccaaaaacccccccccccchhhhhhhhhhggpoooooooffffaaaaccccc
+abccaacccccccacaaaccccccccccccccccaaaaacccccccccccccccccccccccchhhhhhhhhggggoooooffffaacaaacccc
+abccccccccccaaaaacaaccccccccccccccaaaaaccccccccccccccccccccccccchhhhhhhhggggggggggffcaacccccccc
+abccccccccccaaaaaaaaccccccccccccccaaaacccaacccccccccccaccccccccccccccaaaaaggggggggfcccccccccccc
+abccccccccccccaaaaaccccaacccccccccaaaacaaaaccccccccaaaaccccccccccccccaaaacaaagggggcccccccccaccc
+abcccccccccccaaaaacccccaacccccccccaaaaaaaaaccccccccaaaaaaccccccccccccaaaccaaaacccccccccccccaaac
+abcccccccccccaacaaccaaaaaaaacccaaaaaaaaaaaccccccccccaaaaccccccccccccccaccccaaacccccccccccccaaaa
+abccccccccccccccaaccaaaaaaaaccaaaaaaaaaaaccccccccccaaaaacccccccccccccccccccccacccccccccccccaaaa
+abccccccccccccccccccccaaaaacccaaaaaaaaaaaacccccccccaacaacccccccccccccccccccccccccccccccccaaaaaa

2022/day-12/inputs/test.txt

@@ -0,0 +1,5 @@
+Sabqponm
+abcryxxl
+accszExk
+acctuvwj
+abdefghi

2022/day-12/src/bin/part_one.rs

@@ -0,0 +1,41 @@
+use std::{env, io};
+
+use aoc_2022_12::{parse_input, Graph};
+use petgraph::algo::dijkstra;
+
+fn main() -> io::Result<()> {
+    let infile_path = env::args().nth(1).expect("input file");
+
+    let result = solve(&infile_path)?;
+
+    println!("{result}");
+
+    Ok(())
+}
+
+fn solve(path: &str) -> io::Result<i32> {
+    let (start, end, points) = parse_input(path)?;
+
+    let graph = Graph::from_edges(points);
+
+    let result = dijkstra(&graph, start, Some(end), |_| 1);
+
+    Ok(result[&end])
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    #[test]
+    fn sample() {
+        let result = solve("inputs/test.txt").unwrap();
+        assert_eq!(31, result)
+    }
+
+    #[test]
+    fn puzzle() {
+        let result = solve("inputs/puzzle.txt").unwrap();
+        assert_eq!(420, result);
+    }
+}

2022/day-12/src/bin/part_two.rs

@@ -0,0 +1,54 @@
+use std::{env, io};
+
+use aoc_2022_12::{parse_input, Graph};
+use itertools::Itertools;
+use petgraph::algo::dijkstra;
+
+fn main() -> io::Result<()> {
+    let infile_path = env::args().nth(1).expect("input file");
+
+    let result = solve(&infile_path)?;
+
+    println!("{result}");
+
+    Ok(())
+}
+
+fn solve(path: &str) -> io::Result<i32> {
+    let (_, end, points) = parse_input(path)?;
+
+    let potential_starting_points = points
+        .iter()
+        .filter_map(|(a, _)| if a.2 == 1 { Some(*a) } else { None })
+        .unique()
+        .collect::<Vec<_>>();
+
+    let graph = Graph::from_edges(points);
+    let result = potential_starting_points
+        .into_iter()
+        .filter_map(|start| {
+            let result = dijkstra(&graph, start, Some(end), |_| 1);
+            result.get(&end).copied()
+        })
+        .min()
+        .unwrap();
+
+    Ok(result)
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    #[test]
+    fn sample() {
+        let result = solve("inputs/test.txt").unwrap();
+        assert_eq!(29, result)
+    }
+
+    #[test]
+    fn puzzle() {
+        let result = solve("inputs/puzzle.txt").unwrap();
+        assert_eq!(414, result);
+    }
+}

2022/day-12/src/lib.rs

@@ -0,0 +1,109 @@
+use std::{
+    collections::HashMap,
+    fs::File,
+    io::{self, BufRead, BufReader},
+    iter,
+    path::Path,
+};
+
+use petgraph::prelude::DiGraphMap;
+
+pub type Graph = DiGraphMap<PointWithHeight, ()>;
+type PointWithHeight = (i32, i32, i32);
+
+pub struct HeightMap {
+    items: HashMap<(i32, i32), i32>,
+    width: i32,
+    height: i32,
+}
+
+impl HeightMap {
+    pub fn new() -> Self {
+        Self {
+            items: HashMap::new(),
+            width: 0,
+            height: 0,
+        }
+    }
+}
+
+pub fn parse_input<P>(
+    path: P,
+) -> io::Result<(
+    PointWithHeight,
+    PointWithHeight,
+    Vec<(PointWithHeight, PointWithHeight)>,
+)>
+where
+    P: AsRef<Path>,
+{
+    let file = File::open(path)?;
+    let mut height_map = HeightMap::new();
+    let mut start_point = None;
+    let mut end_point = None;
+
+    for (line_idx, line) in BufReader::new(file).lines().enumerate() {
+        let line = line?;
+
+        for (cell_idx, cell) in line.chars().enumerate() {
+            height_map.width = (cell_idx + 1) as i32;
+
+            let point = (line_idx as i32, cell_idx as i32);
+
+            let height = if cell == 'S' {
+                start_point = Some((point.0, point.1, 1));
+                1
+            } else if cell == 'E' {
+                end_point = Some((point.0, point.1, 26));
+                26
+            } else {
+                (cell as u8 - 96).into()
+            };
+
+            height_map.items.insert(point, height);
+        }
+
+        height_map.height += 1
+    }
+
+    let edges = build_edges(&height_map);
+    let start_point = start_point.expect("no start point");
+    let end_point = end_point.expect("no end point");
+
+    Ok((start_point, end_point, edges))
+}
+
+fn build_edges(map: &HeightMap) -> Vec<(PointWithHeight, PointWithHeight)> {
+    map.items
+        .keys()
+        .flat_map(|point @ (x, y)| {
+            let neighbors =
+                [(-1, 0), (0, 1), (1, 0), (0, -1)]
+                    .iter()
+                    .filter_map(move |(nx, ny)| {
+                        let dx = x + nx;
+                        let dy = y + ny;
+
+                        let inside_bounds =
+                            (0..map.height).contains(&dx) && (0..map.width).contains(&dy);
+
+                        if inside_bounds {
+                            Some((dx, dy))
+                        } else {
+                            None
+                        }
+                    });
+
+            iter::repeat(point).zip(neighbors).filter_map(|(a, b)| {
+                let height_self = map.items[&(a.0, a.1)];
+                let height_neighbor = map.items[&(b.0, b.1)];
+
+                if height_self + 1 >= height_neighbor {
+                    Some(((a.0, a.1, height_self), (b.0, b.1, height_neighbor)))
+                } else {
+                    None
+                }
+            })
+        })
+        .collect()
+}

README.md

@@ -9,4 +9,4 @@
 -   [2019](2019/README.md) (0% completed)
 -   [2020](2020/README.md) (20% completed)
 -   [2021](2021/README.md) (68% completed)
--   [2022](2022/README.md) (42% completed)
+-   [2022](2022/README.md) (46% completed)