first two days

Cargo.lock

@@ -23,10 +23,21 @@ version = "0.12.0"
 dependencies = [
  "chrono",
  "dhat",
+ "itertools",
  "pico-args",
+ "regex",
  "tinyjson",
 ]
 
+[[package]]
+name = "aho-corasick"
+version = "1.1.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ddd31a130427c27518df266943a5308ed92d4b226cc639f5a8f1002816174301"
+dependencies = [
+ "memchr",
+]
+
 [[package]]
 name = "android-tzdata"
 version = "0.1.1"
@@ -126,6 +137,12 @@ dependencies = [
  "thousands",
 ]
 
+[[package]]
+name = "either"
+version = "1.15.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "48c757948c5ede0e46177b7add2e67155f70e33c07fea8284df6576da70b3719"
+
 [[package]]
 name = "gimli"
 version = "0.28.1"
@@ -155,6 +172,15 @@ dependencies = [
  "cc",
 ]
 
+[[package]]
+name = "itertools"
+version = "0.14.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2b192c782037fadd9cfa75548310488aabdbf3d2da73885b31bd0abd03351285"
+dependencies = [
+ "either",
+]
+
 [[package]]
 name = "itoa"
 version = "1.0.9"
@@ -303,6 +329,35 @@ dependencies = [
  "bitflags",
 ]
 
+[[package]]
+name = "regex"
+version = "1.12.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "843bc0191f75f3e22651ae5f1e72939ab2f72a4bc30fa80a066bd66edefc24d4"
+dependencies = [
+ "aho-corasick",
+ "memchr",
+ "regex-automata",
+ "regex-syntax",
+]
+
+[[package]]
+name = "regex-automata"
+version = "0.4.13"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5276caf25ac86c8d810222b3dbb938e512c55c6831a10f3e6ed1c93b84041f1c"
+dependencies = [
+ "aho-corasick",
+ "memchr",
+ "regex-syntax",
+]
+
+[[package]]
+name = "regex-syntax"
+version = "0.8.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7a2d987857b319362043e95f5353c0535c1f58eec5336fdfcf626430af7def58"
+
 [[package]]
 name = "rustc-demangle"
 version = "0.1.23"

Cargo.toml

@@ -24,7 +24,9 @@ test_lib = []
 # Template dependencies
 chrono = { version = "0.4.38", optional = true }
 dhat = { version = "0.3.3", optional = true }
+itertools = "0.14.0"
 pico-args = "0.5.0"
+regex = "1.12.2"
 tinyjson = "2.5.1"
 
 # Solution dependencies

README.md

@@ -6,6 +6,15 @@ Solutions for [Advent of Code](https://adventofcode.com/) in [Rust](https://www.
 
 <!--- advent_readme_stars table --->
 
+<!--- benchmarking table --->
+## Benchmarks
+
+| Day | Part 1 | Part 2 |
+| :---: | :---: | :---:  |
+| [Day 1](./src/bin/01.rs) | `881.1µs` | `849.0µs` |
+| [Day 2](./src/bin/02.rs) | `225.7ms` | `250.4ms` |
+
+**Total: 477.83ms**
 <!--- benchmarking table --->
 
 ---

data/examples/01.txt

@@ -0,0 +1,10 @@
+L68
+L30
+R48
+L5
+R60
+L55
+L1
+L99
+R14
+L82

data/examples/02.txt

@@ -0,0 +1 @@
+11-22,95-115,998-1012,1188511880-1188511890,222220-222224,1698522-1698528,446443-446449,38593856-38593862,565653-565659,824824821-824824827,2121212118-2121212124

src/bin/01.rs

@@ -0,0 +1,56 @@
+advent_of_code::solution!(1);
+use regex::Regex;
+
+pub fn part_one(input: &str) -> Option<u64> {
+    let dir_regex = Regex::new(r"(.)(\d+)").unwrap();
+
+    let (hits, _total) = dir_regex.captures_iter(input).fold((0u32, 50i32), |(hits, total), cap| {
+        let (_, [direction, value_str]) = cap.extract();
+        let value = value_str.parse::<i32>().unwrap();
+
+        let new_total = (total + 100 + if direction == "L" { -1i32 } else { 1 } * value) % 100;
+        let new_hits = if new_total == 0 { hits + 1 } else { hits };
+
+        // println!("{} + {} {} = {}", total, direction, value, new_total);
+
+        (new_hits, new_total)
+    });
+
+    Some(hits as u64)
+}
+
+pub fn part_two(input: &str) -> Option<u64> {
+        let dir_regex = Regex::new(r"(.)(\d+)").unwrap();
+
+    let (hits, _total) = dir_regex.captures_iter(input).fold((0u32, 50i32), |(hits, total), cap| {
+        let (_, [direction, value_str]) = cap.extract();
+        let value: i32 = value_str.parse::<i32>().unwrap();
+
+        let new_total_unmod = total + if direction == "L" { -1i32 } else { 1 } * value;
+        let new_total = (new_total_unmod % 100 + 100) % 100;
+        let clicks_past_zero = (new_total_unmod / 100).abs() as u32 + if total != 0 && new_total_unmod <= 0 { 1 } else { 0 };
+
+        // println!("{} + {} {} = {} ({} total clicks, {} new)", total, direction, value, new_total, hits + clicks_past_zero, clicks_past_zero);
+
+        (hits + clicks_past_zero, new_total)
+    });
+
+    Some(hits as u64)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_part_one() {
+        let result = part_one(&advent_of_code::template::read_file("examples", DAY));
+        assert_eq!(result, Some(3));
+    }
+
+    #[test]
+    fn test_part_two() {
+        let result = part_two(&advent_of_code::template::read_file("examples", DAY));
+        assert_eq!(result, Some(6));
+    }
+}

src/bin/02.rs

@@ -0,0 +1,76 @@
+advent_of_code::solution!(2);
+use itertools::Itertools;
+
+pub fn part_one(input: &str) -> Option<u64> {
+    let mut sum: u64 = 0;
+    for range in input.split(',') {
+        // println!("Range is: {}", range);
+        let values = range.split('-').map(|v| v.trim().parse::<u64>().unwrap()).collect::<Vec<u64>>();
+        let start = values[0];
+        let end = values[1];
+        // println!("Range: {}-{}", start, end);
+        for n in start..=end {
+            let s = n.to_string();
+            if s.chars().collect_vec().len() % 2 != 0 {
+                continue;
+            }
+            let first_half = &s[0..(s.len() / 2)];
+            let second_half = &s[(s.len() / 2)..s.len()];
+            if first_half == second_half {
+                // println!("  Number: {} ({} | {})", n, first_half, second_half);
+                sum += n;
+            }
+        }
+    }
+    Some(sum)
+}
+
+pub fn part_two(input: &str) -> Option<u64> {
+    let mut sum: u64 = 0;
+    for range in input.split(',') {
+        // println!("Range is: {}", range);
+        let values = range.split('-').map(|v| v.trim().parse::<u64>().unwrap()).collect::<Vec<u64>>();
+        let start = values[0];
+        let end = values[1];
+        // println!("Range: {}-{}", start, end);
+        for n in start..=end {
+            let s = n.to_string();
+            let total_chars = s.chars().collect_vec().len();
+            'takeBy: for take_by in 1..=(total_chars / 2) {
+                if total_chars % take_by != 0 {
+                    continue;
+                }
+            let mut idx = 0;
+            while idx + 2 * take_by <= total_chars {
+                let part = &s[idx..(idx + take_by)];
+                let next_part = &s[(idx + take_by)..(idx + 2 * take_by)];
+                if part != next_part {
+                    continue 'takeBy;
+                }
+                idx += take_by;
+            }
+            // println!("  Number: {} (take by {})", n, take_by);
+            sum += n;
+            break; // do not continue checking other take_by values
+            }
+        }
+    }
+    Some(sum)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_part_one() {
+        let result = part_one(&advent_of_code::template::read_file("examples", DAY));
+        assert_eq!(result, Some(1227775554));
+    }
+
+    #[test]
+    fn test_part_two() {
+        let result = part_two(&advent_of_code::template::read_file("examples", DAY));
+        assert_eq!(result, Some(4174379265));
+    }
+}