add day14

2023/Cargo.toml

@@ -15,7 +15,7 @@ members = [
   "day11",
   "day12",
   "day13",
-  # "day14",
+  "day14",
   # "day15",
   # "day16",
   # "day17",

2023/day14/.gitignore

@@ -0,0 +1,19 @@
+input.txt
+flamegraph.svg
+perf.data*
+### Rust
+# Generated by Cargo
+# will have compiled files and executables
+debug/
+target/
+
+# Remove Cargo.lock from gitignore if creating an executable, leave it for libraries
+# More information here https://doc.rust-lang.org/cargo/guide/cargo-toml-vs-cargo-lock.html
+Cargo.lock
+
+# These are backup files generated by rustfmt
+**/*.rs.bk
+
+# MSVC Windows builds of rustc generate these, which store debugging information
+*.pdb
+

2023/day14/Cargo.toml

@@ -0,0 +1,11 @@
+[package]
+name = "day14"
+authors = ["mirsella <[email protected]>"]
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+
+grid = { git = "https://github.com/mirsella/grid" }

2023/day14/build.rs

@@ -0,0 +1,28 @@
+use std::fs::File;
+use std::io::{self, Read};
+use std::path::PathBuf;
+use std::{env, fs};
+
+fn replace_in_file(file_path: &PathBuf, old: &str, new: &str) -> io::Result<()> {
+    let mut contents = String::new();
+    File::open(file_path)?.read_to_string(&mut contents)?;
+    let new_contents = contents.replace(old, new);
+    if contents != new_contents {
+        println!("Updating {}", file_path.display());
+        fs::write(file_path, new_contents)?;
+    }
+    Ok(())
+}
+
+fn main() -> io::Result<()> {
+    let pkg_name = env::var("CARGO_PKG_NAME").unwrap();
+    replace_in_file(
+        &"../Cargo.toml".into(),
+        &format!("# \"{pkg_name}\""),
+        &format!("\"{pkg_name}\""),
+    )?;
+
+    replace_in_file(&"./Cargo.toml".into(), "\n[workspace]", "")?;
+
+    Ok(())
+}

2023/day14/src/main.rs

@@ -0,0 +1,103 @@
+use std::collections::HashMap;
+
+use grid::Grid;
+
+fn slide_up(col: &mut [&mut char]) {
+    let mut hard: isize = -1;
+    let mut last: isize = 0;
+    for i in 0..col.len() {
+        match col[i] {
+            '#' => {
+                hard = i as isize;
+                last = 0;
+            }
+            'O' => {
+                *col[i] = '.';
+                *col[(hard + last + 1) as usize] = 'O';
+                last += 1;
+            }
+            _ => (),
+        }
+    }
+}
+
+fn calculate_weight<'a>(col: impl Iterator<Item = &'a char>, row_len: usize) -> usize {
+    col.enumerate().fold(
+        0,
+        |acc, (i, &c)| {
+            if c == 'O' {
+                acc + (row_len - i)
+            } else {
+                acc
+            }
+        },
+    )
+}
+
+fn part1(input: &str) -> usize {
+    let vec = input.chars().filter(|&c| c != '\n').collect::<Vec<_>>();
+    let mut grid = Grid::from_vec(vec, input.find('\n').unwrap());
+    (0..grid.cols())
+        .map(|i| {
+            let mut col = grid.iter_col_mut(i).collect::<Vec<_>>();
+            slide_up(col.as_mut_slice());
+            calculate_weight(grid.iter_col(i), grid.cols())
+        })
+        .sum()
+}
+fn part2(input: &str, cycle: usize) -> usize {
+    let vec = input.chars().filter(|&c| c != '\n').collect::<Vec<_>>();
+    let mut grid = Grid::from_vec(vec, input.find('\n').unwrap());
+    let mut map = HashMap::with_capacity(1000);
+    let mut count = 0;
+    let (spins, cycle_len) = loop {
+        count += 1;
+        for _ in 0..4 {
+            // FIX: 99% performance loss on this loop
+            (0..grid.cols())
+                .for_each(|i| slide_up(grid.iter_col_mut(i).collect::<Vec<_>>().as_mut_slice()));
+            grid.rotate_right();
+        }
+        if let Some(dup) = map.insert(grid.iter().copied().collect::<Vec<_>>(), count) {
+            break (count, count - dup);
+        }
+    };
+    let spins_left = (cycle - spins) % cycle_len;
+    for _ in 0..spins_left {
+        for _ in 0..4 {
+            (0..grid.cols())
+                .for_each(|i| slide_up(grid.iter_col_mut(i).collect::<Vec<_>>().as_mut_slice()));
+            grid.rotate_right();
+        }
+    }
+    (0..grid.cols())
+        .map(|i| calculate_weight(grid.iter_col(i), grid.cols()))
+        .sum()
+}
+fn main() {
+    let input = include_str!("../input.txt");
+    println!("Part 1: {}", part1(input));
+    println!("Part 2: {}", part2(input, 1000000000));
+}
+
+#[cfg(test)]
+mod tests {
+    const INPUT: &str = "O....#....
+O.OO#....#
+.....##...
+OO.#O....O
+.O.....O#.
+O.#..O.#.#
+..O..#O..O
+.......O..
+#....###..
+#OO..#....";
+    #[test]
+    fn part1() {
+        assert_eq!(super::part1(INPUT), 136);
+    }
+    #[test]
+    fn part2() {
+        assert_eq!(super::part2(INPUT, 1000000000), 64);
+    }
+}