feat: setup & day 1

2025/.gitignore

···
+/target
+inputs

2025/Cargo.lock

···
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 4
+
+[[package]]
+name = "anyhow"
+version = "1.0.100"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a23eb6b1614318a8071c9b2521f36b424b2c83db5eb3a0fead4a6c0809af6e61"
+
+[[package]]
+name = "aoc2025"
+version = "0.1.0"
+dependencies = [
+ "anyhow",
+]

2025/Cargo.toml

···
+[package]
+name = "aoc2025"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
+anyhow = "1.0.100"

2025/src/days/mod.rs

···
+pub mod one;

2025/src/days/one/mod.rs

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+pub mod secret_entrance;

2025/src/days/one/secret_entrance.rs

···
+pub fn main() -> anyhow::Result<()> {
+    crate::run("Secret Entrance", "inputs/day1.txt", parse, part_a, part_b)
+}
+
+fn parse(input: &str) -> Vec<i32> {
+    input
+        .lines()
+        .filter(|line| !line.is_empty())
+        .filter_map(|line| line.replace("L", "-").replace("R", "").parse().ok())
+        .collect()
+}
+
+fn part_a(input: Vec<i32>) -> usize {
+    input
+        .iter()
+        .scan(50, |state, &rotation| {
+            *state += rotation;
+            Some(*state)
+        })
+        .filter(|&state| state % 100 == 0)
+        .count()
+}
+
+fn part_b(input: Vec<i32>) -> usize {
+    input
+        .iter()
+        .scan(50, |state, &rotation| {
+            let mut passes = (rotation / 100).abs() as usize;
+            let turn = rotation % 100;
+            if *state + turn <= 0 && *state != 0 || 99 < *state + turn {
+                passes += 1;
+            }
+            *state = (*state + turn).rem_euclid(100);
+            Some(passes)
+        })
+        .sum()
+}

2025/src/lib.rs

···
+pub mod days;
+
+use std::{fmt::Display, fs, time::Instant};
+
+use anyhow::Result;
+
+pub fn run<T, P, A, B, RA, RB>(
+    name: &str,
+    input_path: &str,
+    parse: P,
+    part_a: A,
+    part_b: B,
+) -> Result<()>
+where
+    T: Clone,
+    P: Fn(&str) -> T,
+    A: Fn(T) -> RA,
+    B: Fn(T) -> RB,
+    RA: Display,
+    RB: Display,
+{
+    let input = parse(&fs::read_to_string(input_path)?);
+
+    let label_a = format!("{name} Part A");
+    println!("{label_a}");
+    println!("{}", "-".repeat(label_a.len()));
+    let part_a_start = Instant::now();
+    println!("Part A answer: {}", part_a(input.clone()));
+    let part_a_elapsed = part_a_start.elapsed();
+    println!("Part A time: {:?}", part_a_elapsed);
+
+    println!();
+
+    let label_b = format!("{name} Part B");
+    println!("{label_b}");
+    println!("{}", "-".repeat(label_b.len()));
+    let part_b_start = Instant::now();
+    println!("Part B answer: {}", part_b(input.clone()));
+    let part_b_elapsed = part_b_start.elapsed();
+    println!("Part B time: {:?}", part_b_elapsed);
+
+    println!();
+
+    println!("Total time: {:?}", part_a_elapsed + part_b_elapsed);
+
+    Ok(())
+}

2025/src/main.rs

···
+fn main() -> anyhow::Result<()> {
+    aoc2025::days::one::secret_entrance::main()?;
+    Ok(())
+}