star five

Cargo.lock

@@ -2,6 +2,53 @@
 # It is not intended for manual editing.
 version = 3
 
+[[package]]
+name = "aho-corasick"
+version = "1.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8e60d3430d3a69478ad0993f19238d2df97c507009a52b3c10addcd7f6bcb916"
+dependencies = [
+ "memchr",
+]
+
 [[package]]
 name = "aoc-2024"
 version = "0.1.0"
+dependencies = [
+ "regex",
+]
+
+[[package]]
+name = "memchr"
+version = "2.7.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "78ca9ab1a0babb1e7d5695e3530886289c18cf2f87ec19a575a0abdce112e3a3"
+
+[[package]]
+name = "regex"
+version = "1.11.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b544ef1b4eac5dc2db33ea63606ae9ffcfac26c1416a2806ae0bf5f56b201191"
+dependencies = [
+ "aho-corasick",
+ "memchr",
+ "regex-automata",
+ "regex-syntax",
+]
+
+[[package]]
+name = "regex-automata"
+version = "0.4.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "809e8dc61f6de73b46c85f4c96486310fe304c434cfa43669d7b40f711150908"
+dependencies = [
+ "aho-corasick",
+ "memchr",
+ "regex-syntax",
+]
+
+[[package]]
+name = "regex-syntax"
+version = "0.8.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2b15c43186be67a4fd63bee50d0303afffcef381492ebe2c5d87f324e1b8815c"

Cargo.toml

@@ -4,3 +4,4 @@ version = "0.1.0"
 edition = "2021"
 
 [dependencies]
+regex = "1.11.1"

src/main.rs

@@ -4,6 +4,7 @@ mod star_one;
 mod star_two;
 mod star_three;
 mod star_four;
+mod star_five;
 
 fn main() {
     let args: Vec<String> = env::args().collect();
@@ -12,6 +13,7 @@ fn main() {
         "2" => star_two::run(),
         "3" => star_three::run(),
         "4" => star_four::run(),
+        "5" => star_five::run(),
         _ => unreachable!(),
     }
 }

src/star_five.rs

@@ -0,0 +1,68 @@
+use std::fs;
+use regex::Regex;
+
+
+pub fn run() {
+    let file = fs::read_to_string("./inputs/star_five.txt").unwrap();
+    let input = file.lines();
+    let str_instructions = filter_instructions(input);
+    let instructions = str_instructions.iter().map(|i| parse_instruction(i)).collect();
+    let result = run_instructions(instructions);
+    println!("Result: {}", result);
+}
+
+fn filter_instructions<'a, I>(str_lines: I) -> Vec<String>
+where
+    I: IntoIterator<Item = &'a str>
+{
+    let re = Regex::new(r"mul\([0-9]{1,3},[0-9]{1,3}\)").unwrap();
+
+    let mut instructions = vec![];
+
+    for str_line in str_lines {
+        instructions.extend(
+            re.find_iter(str_line).map(|s| String::from(s.as_str())).into_iter()
+        );
+    }
+
+    instructions
+}
+
+fn parse_instruction(instruction: &str) -> (isize, isize) {
+    let re = Regex::new(r"[0-9]{1,3},[0-9]{1,3}").unwrap();
+    let substring = re.find(instruction).unwrap().as_str();
+    let nums: Vec<isize> = substring.split(",").map(|s| s.to_string().parse::<isize>().unwrap()).collect();
+    (nums[0], nums[1])
+}
+
+fn run_instructions(instructions: Vec<(isize, isize)>) -> isize {
+    instructions.iter().map(|&e| e.0 * e.1).reduce(|a, b| a + b).unwrap_or(0)
+}
+
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_filter_instructions() {
+        assert_eq!(
+            filter_instructions(vec!["xmul(2,4)%&mul[3,7]!@^do_not_mul(5,5)+mul(32,64]then(mul(11,8)mul(8,5))"]),
+            vec!["mul(2,4)", "mul(5,5)", "mul(11,8)", "mul(8,5)"],
+        )
+    }
+
+    #[test]
+    fn test_parse_instruction() {
+        assert_eq!(parse_instruction("mul(2,4)"), (2, 4));
+        assert_eq!(parse_instruction("mul(5,5)"), (5, 5));
+        assert_eq!(parse_instruction("mul(11,8)"), (11, 8));
+        assert_eq!(parse_instruction("mul(8,5)"), (8, 5));
+    }
+
+    #[test]
+    fn test_run_instructions() {
+        assert_eq!(run_instructions(vec![(2, 4), (5, 5), (11, 8), (8, 5)]), 161);
+        assert_eq!(run_instructions(vec![]), 0);
+    }
+}