feat: day 7

Cargo.toml

@@ -28,6 +28,7 @@ itertools = "0.13.0"
 pico-args = "0.5.0"
 rayon = "1.10.0"
 regex = "1.11.1"
+strum = { version = "0.26.3", features = ["derive"] }
 tinyjson = "2.5.1"
 
 # Solution dependencies

README.md

@@ -22,14 +22,9 @@ Solutions for [Advent of Code](https://adventofcode.com/) in [Rust](https://www.
 
 | Day | Part 1 | Part 2 |
 | :---: | :---: | :---:  |
-| [Day 1](./src/bin/01.rs) | `52.5µs` | `83.5µs` |
-| [Day 2](./src/bin/02.rs) | `179.5µs` | `390.3µs` |
-| [Day 3](./src/bin/03.rs) | `358.1µs` | `335.4µs` |
-| [Day 4](./src/bin/04.rs) | `5.8ms` | `110.4µs` |
-| [Day 5](./src/bin/05.rs) | `1.5ms` | `36.2ms` |
-| [Day 6](./src/bin/06.rs) | `632.3µs` | `184.0ms` |
-
-**Total: 229.64ms**
+| [Day 7](./src/bin/07.rs) | `4.8ms` | `254.2ms` |
+
+**Total: 259.00ms**
 <!--- benchmarking table --->
 
 ---

data/examples/07.txt

@@ -0,0 +1,9 @@
+190: 10 19
+3267: 81 40 27
+83: 17 5
+156: 15 6
+7290: 6 8 6 15
+161011: 16 10 13
+192: 17 8 14
+21037: 9 7 18 13
+292: 11 6 16 20

src/bin/07.rs

@@ -0,0 +1,79 @@
+advent_of_code::solution!(7);
+
+use itertools::Itertools;
+use rayon::prelude::*;
+use strum::{EnumIter, IntoEnumIterator};
+
+#[derive(Debug, EnumIter, Clone)]
+enum Operation {
+    Concat,
+    Add,
+    Mul,
+}
+
+fn solve(input: &str, skip: usize) -> Option<u64> {
+    Some(
+        input
+            .par_lines()
+            .map(|line| {
+                let mut parts = line.split(": ");
+                let result = parts.next().unwrap().parse::<u64>().unwrap();
+                let numbers = parts
+                    .next()
+                    .unwrap()
+                    .split_whitespace()
+                    .map(|n| n.parse::<u64>().unwrap())
+                    .collect::<Vec<u64>>();
+                (result, numbers)
+            })
+            .filter(|(result, numbers)| {
+                (0..numbers.len() - 1)
+                    .map(|_| Operation::iter().skip(skip))
+                    .multi_cartesian_product()
+                    .any(|c| {
+                        let mut c = c.into_iter();
+                        numbers.iter().map(|x| *x).reduce(|acc, n| {
+                            let op = c.next().unwrap();
+                            match op {
+                                Operation::Add => acc + n,
+                                Operation::Mul => acc * n,
+                                Operation::Concat => {
+                                    let mut spacer = 1;
+                                    while n / spacer > 0 {
+                                        spacer *= 10;
+                                    }
+                                    acc * spacer + n
+                                }
+                            }
+                        }) == Some(*result)
+                    })
+            })
+            .map(|(result, _)| result)
+            .sum::<u64>(),
+    )
+}
+
+pub fn part_one(input: &str) -> Option<u64> {
+    solve(input, 1)
+}
+
+pub fn part_two(input: &str) -> Option<u64> {
+    solve(input, 0)
+}
+
+#[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(3749));
+    }
+
+    #[test]
+    fn test_part_two() {
+        let result = part_two(&advent_of_code::template::read_file("examples", DAY));
+        assert_eq!(result, Some(11387));
+    }
+}