From 9adb5887bb960037bcd9ac0cc3c7ebbd65f6437f Mon Sep 17 00:00:00 2001
From: timeshifter <timeshifter@sumatrae>
Date: Sun, 21 Jun 2026 21:44:46 +0200
Subject: [PATCH] add day 8 through 10

---
 day08/Cargo.lock  |  54 +++++++++
 day08/Cargo.toml  |   7 ++
 day08/input.txt   | 300 ++++++++++++++++++++++++++++++++++++++++++++++
 day08/src/main.rs |  49 ++++++++
 day09/Cargo.lock  |  25 ++++
 day09/Cargo.toml  |   7 ++
 day09/input.txt   |  28 +++++
 day09/src/main.rs |  68 +++++++++++
 day10/Cargo.lock  |   7 ++
 day10/Cargo.toml  |   6 +
 day10/src/main.rs |  96 +++++++++++++++
 11 files changed, 647 insertions(+)
 create mode 100644 day08/Cargo.lock
 create mode 100644 day08/Cargo.toml
 create mode 100644 day08/input.txt
 create mode 100644 day08/src/main.rs
 create mode 100644 day09/Cargo.lock
 create mode 100644 day09/Cargo.toml
 create mode 100644 day09/input.txt
 create mode 100644 day09/src/main.rs
 create mode 100644 day10/Cargo.lock
 create mode 100644 day10/Cargo.toml
 create mode 100644 day10/src/main.rs

diff --git a/day08/Cargo.lock b/day08/Cargo.lock
new file mode 100644
index 0000000..41e54f5
--- /dev/null
+++ b/day08/Cargo.lock
@@ -0,0 +1,54 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 4
+
+[[package]]
+name = "aho-corasick"
+version = "1.1.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ddd31a130427c27518df266943a5308ed92d4b226cc639f5a8f1002816174301"
+dependencies = [
+ "memchr",
+]
+
+[[package]]
+name = "day08"
+version = "0.1.0"
+dependencies = [
+ "regex",
+]
+
+[[package]]
+name = "memchr"
+version = "2.8.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "88904434abc2901f197fe8cc55f0445e7ded921dba5911dad2e2b39b48e663c4"
+
+[[package]]
+name = "regex"
+version = "1.12.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f1292b7759ae1cb9ec195452d1390a074f0cd8541ab7a5a8c31cd6db45d4a6ba"
+dependencies = [
+ "aho-corasick",
+ "memchr",
+ "regex-automata",
+ "regex-syntax",
+]
+
+[[package]]
+name = "regex-automata"
+version = "0.4.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6e1dd4122fc1595e8162618945476892eefca7b88c52820e74af6262213cae8f"
+dependencies = [
+ "aho-corasick",
+ "memchr",
+ "regex-syntax",
+]
+
+[[package]]
+name = "regex-syntax"
+version = "0.8.11"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d6f6ff9a378485b298a5286656da665ba74413d36db0979633275d2e708145d4"
diff --git a/day08/Cargo.toml b/day08/Cargo.toml
new file mode 100644
index 0000000..3ced52e
--- /dev/null
+++ b/day08/Cargo.toml
@@ -0,0 +1,7 @@
+[package]
+name = "day08"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
+regex = "1.12.4"
diff --git a/day08/input.txt b/day08/input.txt
new file mode 100644
index 0000000..94538e7
--- /dev/null
+++ b/day08/input.txt
@@ -0,0 +1,300 @@
+"qxfcsmh"
+"ffsfyxbyuhqkpwatkjgudo"
+"byc\x9dyxuafof\\\xa6uf\\axfozomj\\olh\x6a"
+"jtqvz"
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+"wzntebpxnnt\"vqndz\"i\x47vvjqo\""
+"higvez\"k\"riewqk"
+"dlkrbhbrlfrp\\damiauyucwhty"
+"d\""
+"qlz"
+"ku"
+"yy\"\"uoao\"uripabop"
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+"tj"
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+"xs"
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+"hey\\"
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diff --git a/day08/src/main.rs b/day08/src/main.rs
new file mode 100644
index 0000000..b21e7ab
--- /dev/null
+++ b/day08/src/main.rs
@@ -0,0 +1,49 @@
+use regex::Regex;
+
+fn main() {
+    let content = std::fs::read_to_string("input.txt").unwrap();
+    let data: Vec<_> = content.lines().collect();
+
+    part1(&data);
+    part2(&data);
+}
+
+fn part2(data: &[&str]) {
+    let mut new_length = 0;
+    let mut old_length = 0;
+
+    let re_quote = Regex::new("\"").unwrap();
+    let re_backslash = Regex::new(r"\\").unwrap();
+
+    for line in data {
+        old_length += line.len();
+        let found = re_quote.replace_all(line, "AA");
+        let found = re_backslash.replace_all(found.as_ref(), "BB");
+
+        new_length += found.len() + 2; // add first and last quote
+    }
+    let result = new_length - old_length;
+    println!("{result}");
+}
+
+fn part1(data: &[&str]) {
+    let mut literal_length = 0;
+    let mut memory_length = 0;
+
+    let re_hex = Regex::new(r"\\x[a-f0-9]{2}").unwrap();
+    let re_backslash = Regex::new(r"\\\\").unwrap();
+    let re_doublequote = Regex::new(r"\x5c\x22").unwrap();
+
+    for line in data {
+        literal_length += line.len();
+        let found = re_hex.replace_all(line, "A");
+        let found = re_backslash.replace_all(found.as_ref(), "B");
+        let found = re_doublequote.replace_all(found.as_ref(), "C");
+
+        memory_length += found.len() - 2; // remove first and last quote
+    }
+    let result = literal_length - memory_length;
+    println!("{result}");
+}
+
+// https://adventofcode.com/2015/day/8
diff --git a/day09/Cargo.lock b/day09/Cargo.lock
new file mode 100644
index 0000000..df91047
--- /dev/null
+++ b/day09/Cargo.lock
@@ -0,0 +1,25 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 4
+
+[[package]]
+name = "day09"
+version = "0.1.0"
+dependencies = [
+ "itertools",
+]
+
+[[package]]
+name = "either"
+version = "1.16.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "91622ff5e7162018101f2fea40d6ebf4a78bbe5a49736a2020649edf9693679e"
+
+[[package]]
+name = "itertools"
+version = "0.15.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8b4baf93f58d4425749ca49a51c50ebab072c5df6994d08fed93541c331481dc"
+dependencies = [
+ "either",
+]
diff --git a/day09/Cargo.toml b/day09/Cargo.toml
new file mode 100644
index 0000000..3eb30c7
--- /dev/null
+++ b/day09/Cargo.toml
@@ -0,0 +1,7 @@
+[package]
+name = "day09"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
+itertools = "0.15.0"
diff --git a/day09/input.txt b/day09/input.txt
new file mode 100644
index 0000000..a56f5e2
--- /dev/null
+++ b/day09/input.txt
@@ -0,0 +1,28 @@
+AlphaCentauri to Snowdin = 66
+AlphaCentauri to Tambi = 28
+AlphaCentauri to Faerun = 60
+AlphaCentauri to Norrath = 34
+AlphaCentauri to Straylight = 34
+AlphaCentauri to Tristram = 3
+AlphaCentauri to Arbre = 108
+Snowdin to Tambi = 22
+Snowdin to Faerun = 12
+Snowdin to Norrath = 91
+Snowdin to Straylight = 121
+Snowdin to Tristram = 111
+Snowdin to Arbre = 71
+Tambi to Faerun = 39
+Tambi to Norrath = 113
+Tambi to Straylight = 130
+Tambi to Tristram = 35
+Tambi to Arbre = 40
+Faerun to Norrath = 63
+Faerun to Straylight = 21
+Faerun to Tristram = 57
+Faerun to Arbre = 83
+Norrath to Straylight = 9
+Norrath to Tristram = 50
+Norrath to Arbre = 60
+Straylight to Tristram = 27
+Straylight to Arbre = 81
+Tristram to Arbre = 90
diff --git a/day09/src/main.rs b/day09/src/main.rs
new file mode 100644
index 0000000..aecdfe0
--- /dev/null
+++ b/day09/src/main.rs
@@ -0,0 +1,68 @@
+use std::collections::HashSet;
+
+use itertools::Itertools;
+
+fn main() {
+    let data = std::fs::read_to_string("input.txt").unwrap();
+    let legs: Vec<_> = data.lines().map(Leg::from_str).collect();
+
+    part1(&legs);
+}
+
+fn part1(legs: &[Leg]) {
+    let mut locations = HashSet::new();
+    for (s, e) in legs.iter().map(|l| (l.from.as_str(), l.to.as_str())) {
+        locations.insert(s);
+        locations.insert(e);
+    }
+
+    let length = locations.len();
+
+    let routes = locations.into_iter().permutations(length).collect_vec();
+
+    let mut sums = vec![];
+
+    for route in routes {
+        let sum: usize = route
+            .iter()
+            .tuple_windows()
+            .map(|(l, r)| find_length(legs, l, r))
+            .sum();
+        sums.push(sum);
+    }
+    sums.sort_unstable();
+    println!("{}\n{}", sums[0], sums.last().unwrap());
+}
+
+fn find_length(legs: &[Leg], a: &str, b: &str) -> usize {
+    for leg in legs {
+        if (leg.from == a || leg.to == a) && (leg.from == b || leg.to == b) {
+            return leg.distance;
+        }
+    }
+    unreachable!()
+}
+
+#[derive(Debug)]
+struct Leg {
+    pub from: String,
+    pub to: String,
+    pub distance: usize,
+}
+
+impl Leg {
+    fn new(from: String, to: String, distance: usize) -> Self {
+        Self { from, to, distance }
+    }
+
+    fn from_str(s: &str) -> Self {
+        let mut segments = s.split_whitespace();
+        let from = segments.next().unwrap().to_string();
+        let to = segments.nth(1).unwrap().to_string();
+        let distance = segments.next_back().unwrap().parse().unwrap();
+
+        Self::new(from, to, distance)
+    }
+}
+
+// https://adventofcode.com/2015/day/9
diff --git a/day10/Cargo.lock b/day10/Cargo.lock
new file mode 100644
index 0000000..6b69a8f
--- /dev/null
+++ b/day10/Cargo.lock
@@ -0,0 +1,7 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 4
+
+[[package]]
+name = "day10"
+version = "0.1.0"
diff --git a/day10/Cargo.toml b/day10/Cargo.toml
new file mode 100644
index 0000000..c52cc13
--- /dev/null
+++ b/day10/Cargo.toml
@@ -0,0 +1,6 @@
+[package]
+name = "day10"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
diff --git a/day10/src/main.rs b/day10/src/main.rs
new file mode 100644
index 0000000..8fd061f
--- /dev/null
+++ b/day10/src/main.rs
@@ -0,0 +1,96 @@
+use std::collections::HashMap;
+
+fn main() {
+    let input = "3113322113";
+
+    part1(input);
+}
+
+fn part1(input: &str) {
+    let mut input: Vec<_> = input.to_string().chars().collect();
+
+    for _ in 0..34 {
+        input = recurse(input);
+    }
+    for c in input {
+        print!("{c}");
+    }
+    println!();
+}
+
+fn recurse(input: Vec<char>) -> Vec<char> {
+    if input.is_empty() {
+        return input;
+    }
+
+    let mut iter = input.iter();
+    let first_digit = *iter.next().unwrap();
+
+    let s = 0;
+    let mut e = 0;
+
+    for next_digit in iter {
+        if first_digit == *next_digit {
+            e += 1
+        } else {
+            break;
+        }
+    }
+
+    let mut result = look_and_say(&input[s..=e]);
+
+    result.append(&mut recurse(input[e + 1..].to_vec()));
+
+    result
+}
+
+fn look_and_say(s: &[char]) -> Vec<char> {
+    if s.is_empty() {
+        return vec![];
+    }
+
+    let binding = s.len().to_string();
+    let length_chars = binding.chars();
+    let mut result = vec![];
+
+    for c in length_chars {
+        result.push(c);
+    }
+
+    result.push(s[0]);
+
+    result
+}
+
+#[cfg(test)]
+mod test {
+    use crate::{look_and_say, recurse};
+
+    #[test]
+    fn basic() {
+        let x = vec!['1'];
+        let result = look_and_say(&x);
+        assert_eq!(result, vec!['1', '1']);
+
+        let x = vec!['1', '1', '1'];
+        let result = look_and_say(&x);
+        assert_eq!(result, vec!['3', '1']);
+
+        let x = vec!['2'];
+        let result = look_and_say(&x);
+        assert_eq!(result, vec!['1', '2']);
+    }
+
+    #[test]
+    fn test_recurse() {
+        // let x = vec!['1'];
+        // let result = recurse(x);
+        // assert_eq!(result, vec!['1', '1']);
+
+        let result = vec!['1', '1', '1', '2', '2', '1'];
+        let result = recurse(result);
+        assert_eq!(result, vec!['3', '1', '2', '2', '1', '1']);
+    }
+}
+
+// https://adventofcode.com/2015/day/10