2024-03 Rust

ReadMe.md

@@ -6,6 +6,7 @@
 
 | Year-Day | Task                                                                           |                                  Scala                                  |                      Rust                      |                                 Others                                 |
 |----------|:-------------------------------------------------------------------------------|:-----------------------------------------------------------------------:|:----------------------------------------------:|:----------------------------------------------------------------------:|
+| 2024-03  | [Mull It Over](https://adventofcode.com/2024/day/3)                            | [Scala](scala2/src/main/scala/jurisk/adventofcode/y2024/Advent03.scala) | [Rust](rust/y2024/src/bin/solution_2024_03.rs) |                                                                        |
 | 2024-02  | [Red-Nosed Reports](https://adventofcode.com/2024/day/2)                       | [Scala](scala2/src/main/scala/jurisk/adventofcode/y2024/Advent02.scala) | [Rust](rust/y2024/src/bin/solution_2024_02.rs) |                                                                        |
 | 2024-01  | [Historian Hysteria](https://adventofcode.com/2024/day/1)                      | [Scala](scala2/src/main/scala/jurisk/adventofcode/y2024/Advent01.scala) | [Rust](rust/y2024/src/bin/solution_2024_01.rs) |                                                                        |
 | 2023-01  | [Trebuchet?!](https://adventofcode.com/2023/day/1)                             | [Scala](scala2/src/main/scala/jurisk/adventofcode/y2023/Advent01.scala) | [Rust](rust/y2023/src/bin/solution_2023_01.rs) |                                                                        |

rust/y2024/Cargo.toml

@@ -11,4 +11,5 @@ workspace = true
 
 [dependencies]
 advent-of-code-common = { path = "../common" }
-itertools.workspace = true
+itertools.workspace = true
+regex.workspace = true

rust/y2024/resources/03-test-00.txt

@@ -0,0 +1 @@
+xmul(2,4)%&mul[3,7]!@^do_not_mul(5,5)+mul(32,64]then(mul(11,8)mul(8,5))

rust/y2024/resources/03-test-01.txt

@@ -0,0 +1 @@
+xmul(2,4)&mul[3,7]!^don't()_mul(5,5)+mul(32,64](mul(11,8)undo()?mul(8,5))

rust/y2024/src/bin/solution_2024_02.rs

@@ -30,12 +30,11 @@ fn valid_diffs_1(row: &[N], range: &RangeInclusive<N>) -> bool {
 #[allow(dead_code)]
 fn valid_diffs_2_straightforward(row: &[N], range: &RangeInclusive<N>) -> bool {
     valid_diffs_1(row, range)
-        || (0 .. row.len())
-            .any(|idx| {
-                let mut row = row.to_vec();
-                row.remove(idx);
-                valid_diffs_1(row.as_slice(), range)
-            })
+        || (0 .. row.len()).any(|idx| {
+            let mut row = row.to_vec();
+            row.remove(idx);
+            valid_diffs_1(row.as_slice(), range)
+        })
 }
 
 fn valid_diffs_2_dp(row: &[N], range: &RangeInclusive<N>) -> bool {

rust/y2024/src/bin/solution_2024_03.rs

@@ -0,0 +1,96 @@
+const DATA: &str = include_str!("../../resources/03.txt");
+
+type R = usize;
+type Data = &'static str;
+
+use regex::Regex;
+
+const MUL: &str = r"mul\((\d+),(\d+)\)";
+const DO: &str = r"do()";
+const DONT: &str = r"don't()";
+
+fn to_regex(s: &str) -> String {
+    s.replace('(', r"\(").replace(')', r"\)")
+}
+
+fn solve(data: &Data, regex: &str) -> Result<R, String> {
+    let regex = Regex::new(regex).map_err(|err| format!("Error compiling regex: {err}"))?;
+
+    let mul = Regex::new(MUL).map_err(|err| format!("Error compiling regex: {err}"))?;
+
+    let mut active = true;
+    let mut result = 0;
+
+    for s in regex.find_iter(data).map(|m| m.as_str()) {
+        if s == DO {
+            active = true;
+        } else if s == DONT {
+            active = false;
+        } else if let Some(captures) = mul.captures(s) {
+            if active {
+                let c_1 = captures.get(1).ok_or(format!("Invalid capture: {s}"))?;
+                let a = c_1
+                    .as_str()
+                    .parse::<usize>()
+                    .map_err(|err| format!("Failed to parse: {err}"))?;
+                let c_2 = captures.get(2).ok_or(format!("Invalid capture: {s}"))?;
+                let b = c_2
+                    .as_str()
+                    .parse::<usize>()
+                    .map_err(|err| format!("Failed to parse: {err}"))?;
+                result += a * b;
+            }
+        } else {
+            return Err(format!("Invalid operation: {s}"));
+        }
+    }
+
+    Ok(result)
+}
+
+fn solve_1(data: &Data) -> Result<R, String> {
+    solve(data, MUL)
+}
+
+fn solve_2(data: &Data) -> Result<R, String> {
+    let regex = [MUL.to_string(), to_regex(DO), to_regex(DONT)].join("|");
+    solve(data, regex.as_str())
+}
+
+fn main() -> Result<(), String> {
+    let result_1 = solve_1(&DATA)?;
+    println!("Part 1: {result_1}");
+
+    let result_2 = solve_2(&DATA)?;
+    println!("Part 2: {result_2}");
+
+    Ok(())
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    const TEST_DATA_0: &str = include_str!("../../resources/03-test-00.txt");
+    const TEST_DATA_1: &str = include_str!("../../resources/03-test-01.txt");
+
+    #[test]
+    fn test_solve_1_test() {
+        assert_eq!(solve_1(&TEST_DATA_0), Ok(2 * 4 + 5 * 5 + 11 * 8 + 8 * 5));
+    }
+
+    #[test]
+    fn test_solve_1_real() {
+        assert_eq!(solve_1(&DATA), Ok(187_825_547));
+    }
+
+    #[test]
+    fn test_solve_2_test() {
+        assert_eq!(solve_2(&TEST_DATA_1), Ok(2 * 4 + 8 * 5));
+    }
+
+    #[test]
+    fn test_solve_2_real() {
+        assert_eq!(solve_2(&DATA), Ok(85_508_223));
+    }
+}