2017 day 1

Author: ictrobot

Cargo.lock

@@ -12,12 +12,13 @@ utils = { path = "../utils" }
 # xtask update dependencies
 year2015 = { path = "../year2015", optional = true }
 year2016 = { path = "../year2016", optional = true }
+year2017 = { path = "../year2017", optional = true }
 
 [features]
 default = ["all-years", "unsafe"]
 # xtask update features
-all-years = ["year2015", "year2016"]
-unsafe = ["year2015?/unsafe", "year2016?/unsafe", "utils/unsafe"]
+all-years = ["year2015", "year2016", "year2017"]
+unsafe = ["year2015?/unsafe", "year2016?/unsafe", "year2017?/unsafe", "utils/unsafe"]
 
 [lints]
 workspace = true

crates/aoc/Cargo.toml

@@ -19,10 +19,16 @@ pub mod year2015 {
 pub mod year2016 {
     pub use ::utils::puzzles_noop as puzzles;
 }
+#[cfg(not(feature = "year2017"))]
+pub mod year2017 {
+    pub use ::utils::puzzles_noop as puzzles;
+}
 #[cfg(feature = "year2015")]
 pub use ::year2015;
 #[cfg(feature = "year2016")]
 pub use ::year2016;
+#[cfg(feature = "year2017")]
+pub use ::year2017;
 
 /// Macro which invokes a callback macro with a list of all implemented puzzle solutions.
 ///
@@ -91,6 +97,7 @@ macro_rules! all_puzzles {
                 // xtask update all_puzzles
                 $crate::year2015::puzzles,
                 $crate::year2016::puzzles,
+                $crate::year2017::puzzles,
 
                 $callback
             ]

crates/aoc/src/years.rs

@@ -0,0 +1,14 @@
+[package]
+name = "year2017"
+authors = { workspace = true }
+edition = { workspace = true }
+license = { workspace = true }
+publish = { workspace = true }
+repository = { workspace = true }
+rust-version = { workspace = true }
+
+[dependencies]
+utils = { path = "../utils" }
+
+[features]
+unsafe = ["utils/unsafe"]

crates/year2017/Cargo.toml

@@ -0,0 +1 @@
+Solutions for [Advent of Code 2017](https://adventofcode.com/2017)

crates/year2017/README.md

@@ -0,0 +1,49 @@
+use utils::prelude::*;
+
+/// Adding matching digits.
+#[derive(Clone, Debug)]
+pub struct Day01<'a> {
+    input: &'a [u8],
+}
+
+impl<'a> Day01<'a> {
+    pub fn new(input: &'a str, _: InputType) -> Result<Self, InputError> {
+        if let Some(b) = input.bytes().find(|b| !b.is_ascii_digit()) {
+            Err(InputError::new(input, b as char, "expected digit"))
+        } else {
+            Ok(Self {
+                input: input.as_bytes(),
+            })
+        }
+    }
+
+    #[must_use]
+    pub fn part1(&self) -> u32 {
+        self.input
+            .iter()
+            .zip(self.input.iter().cycle().skip(1))
+            .map(|(&a, &b)| if a == b { (a - b'0') as u32 } else { 0 })
+            .sum()
+    }
+
+    #[must_use]
+    pub fn part2(&self) -> u32 {
+        self.input
+            .iter()
+            .zip(self.input.iter().cycle().skip(self.input.len() / 2))
+            .map(|(&a, &b)| if a == b { (a - b'0') as u32 } else { 0 })
+            .sum()
+    }
+}
+
+examples!(Day01<'_> -> (u32, u32) [
+    {input: "1122", part1: 3},
+    {input: "1111", part1: 4},
+    {input: "1234", part1: 0},
+    {input: "91212129", part1: 9},
+    {input: "1212", part2: 6},
+    {input: "1221", part2: 0},
+    {input: "123425", part2: 4},
+    {input: "123123", part2: 12},
+    {input: "12131415", part2: 4},
+]);

crates/year2017/src/day01.rs

@@ -0,0 +1,6 @@
+#![doc = include_str!("../README.md")]
+#![cfg_attr(not(feature = "unsafe"), forbid(unsafe_code))]
+
+utils::year!(2017 => year2017, ${
+    1 => day01::Day01<'_>,
+});