2024.3

1 files changed, 46 insertions, 0 deletions

diff --git a/2024/3/src/main.rs b/2024/3/src/main.rs
new file mode 100644
index 0000000..cadc1fe
--- /dev/null
+++ b/2024/3/src/main.rs
@@ -0,0 +1,46 @@
+use regex::Regex;
+
+const INPUT_FILE: &str = "input";
+
+fn p1(input: &str) {
+    let re = Regex::new(r"mul\(([0-9]{1,3}),([0-9]{1,3})\)").unwrap();
+
+    let mut result: u32 = 0;
+    for (_, [x, y]) in re.captures_iter(input).map(|m| m.extract()) {
+        result += x.parse::<u32>().unwrap() * y.parse::<u32>().unwrap();
+    }
+
+    println!("Result: {}", result);
+}
+
+fn p2(input: &str) {
+    let re = Regex::new(r"do\(\)|don't\(\)|mul\(([0-9]{1,3}),([0-9]{1,3})\)").unwrap();
+
+    let mut doing = true;
+    let mut result: u32 = 0;
+    for m in re.captures_iter(input) {
+        let mut it = m.iter();
+        match it.next().unwrap().map(|m| m.as_str()) {
+            Some("do()") => doing = true,
+            Some("don't()") => doing = false,
+            Some(mul) if doing && mul.starts_with("mul") => {
+                if let [x, y] = it
+                    .flatten()
+                    .map(|m| m.as_str().parse::<u32>().unwrap())
+                    .collect::<Vec<u32>>()[..]
+                {
+                    result += x * y;
+                }
+            }
+            _ => (),
+        }
+    }
+
+    println!("Result: {}", result);
+}
+
+fn main() {
+    let input = std::fs::read_to_string(INPUT_FILE).unwrap();
+    p1(&input);
+    p2(&input);
+}