daay 13 done day 14 added

day13/src/main.rs

@@ -0,0 +1,119 @@
+#![warn(clippy::all, clippy::pedantic)]
+
+use std::{
+    cmp::Ordering::{Equal, Greater, Less},
+    fs,
+};
+
+use nom::{
+    branch::alt,
+    bytes::complete::tag,
+    character::complete::{self, newline},
+    multi::{separated_list0, separated_list1},
+    sequence::{delimited, separated_pair},
+    Parser,
+};
+
+#[derive(Debug, Eq)]
+pub enum Checker {
+    Num(u32),
+    Array(Vec<Checker>),
+}
+
+impl Checker {
+    /// # Errors
+    ///
+    /// returns an `nom::err::Error<&str>` if there is problems parsing
+    pub fn parse(input: &str) -> nom::IResult<&str, Self, nom::error::Error<&str>> {
+        alt((
+            complete::u32.map(Self::Num),
+            delimited(tag("["), separated_list0(tag(","), Self::parse), tag("]")).map(Self::Array),
+        ))(input)
+    }
+}
+
+impl PartialEq for Checker {
+    fn eq(&self, other: &Self) -> bool {
+        match (self, other) {
+            (Self::Num(l0), Self::Num(r0)) => l0 == r0,
+            (Self::Array(l0), Self::Array(r0)) => l0 == r0,
+            (Self::Num(l0), Self::Array(r0)) => &vec![Self::Num(*l0)] == r0,
+            (Self::Array(l0), Self::Num(r0)) => l0 == &vec![Self::Num(*r0)],
+        }
+    }
+}
+
+impl PartialOrd for Checker {
+    fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
+        Some(self.cmp(other))
+    }
+}
+
+impl Ord for Checker {
+    fn cmp(&self, other: &Self) -> std::cmp::Ordering {
+        match (self, other) {
+            (Self::Array(a), Self::Array(b)) => a.cmp(b),
+            (Self::Num(a), Self::Num(b)) => a.cmp(b),
+            (Self::Array(a), Self::Num(b)) => a.cmp(&vec![Self::Num(*b)]),
+            (Self::Num(a), Self::Array(b)) => vec![Self::Num(*a)].cmp(b),
+        }
+    }
+}
+
+pub struct Together {
+    pub left: Checker,
+    pub right: Checker,
+}
+
+impl Together {
+    /// # Errors
+    ///
+    /// returns an `nom::err::Error<&str>` if there is problems parsing
+    pub fn parse(input: &str) -> nom::IResult<&str, Self, nom::error::Error<&str>> {
+        separated_pair(Checker::parse, newline, Checker::parse)(input)
+            .map(|(input, (left, right))| (input, Self { left, right }))
+    }
+}
+
+/// # Errors
+///
+/// returns an `nom::err::Error<&str>` if there is problems parsing
+pub fn parse_data(input: &str) -> nom::IResult<&str, Vec<Together>, nom::error::Error<&str>> {
+    separated_list1(tag("\n\n"), Together::parse)(input)
+}
+
+fn main() {
+    let file = fs::read_to_string("./input.txt").unwrap();
+    let (_, all) = parse_data(&file).unwrap();
+    let part1 = all
+        .iter()
+        .enumerate()
+        .filter_map(|(i, Together { left, right })| match left.cmp(right) {
+            Less => Some(i + 1),
+            Equal => panic!(),
+            Greater => None,
+        })
+        .sum::<usize>();
+    let two = Checker::Array(vec![Checker::Array(vec![Checker::Num(2)])]);
+    let six = Checker::Array(vec![Checker::Array(vec![Checker::Num(6)])]);
+    let mut p2 = all
+        .iter()
+        .flat_map(|Together { left, right }| [left, right])
+        .chain([&two, &six])
+        .collect::<Vec<_>>();
+    p2.sort();
+
+    let i2 = p2
+        .iter()
+        .enumerate()
+        .find_map(|(i, b)| if *b == &two { Some(i + 1) } else { None })
+        .unwrap();
+    let i6 = p2
+        .iter()
+        .enumerate()
+        .find_map(|(i, b)| if *b == &six { Some(i + 1) } else { None })
+        .unwrap();
+    let part2 = i2 * i6;
+    println!("Part 1: {part1}");
+    println!("Part 2: {part2}");
+}