1 files changed, 56 insertions, 0 deletions
diff --git a/2024/day03.rs b/2024/day03.rs
new file mode 100644
index 0000000..926329c
--- /dev/null
+++ b/2024/day03.rs
@@ -0,0 +1,56 @@
+#![allow(dead_code)]
+#![allow(unused_variables)]
+#![allow(unused_mut)]
+use regex::Regex;
+use std::env;
+use std::fs::File;
+use std::io::Read;
+
+fn main() {
+    let args: Vec<String> = env::args().collect();
+    let filename = if args.len() == 1 {
+        "in/".to_owned() + args[0].split('/').last().unwrap() + ".pzl"
+    } else {
+        args[1].clone()
+    };
+    let mut f = File::open(filename).expect("cannot open file");
+    let mut content = String::new();
+    f.read_to_string(&mut content).expect("cannot read file");
+    let lines = content.trim_end().split("\n");
+
+    let re = Regex::new(r"mul\((?<a>[0-9]+),(?<b>[0-9]+)\)").unwrap();
+    let mut res1 = 0;
+    for line in lines.clone() {
+        res1 += re
+            .captures_iter(line)
+            .map(|caps| {
+                let p = |name| caps.name(name).unwrap().as_str().parse::<i32>().unwrap();
+                p("a") * p("b")
+            })
+            .fold(0, |a, b| a + b);
+    }
+
+    let re_m = Regex::new(r"^mul\((?<a>[0-9]+),(?<b>[0-9]+)\)").unwrap();
+    let re_do = Regex::new(r"^do\(\)").unwrap();
+    let re_dont = Regex::new(r"^don't\(\)").unwrap();
+    let mut res2 = 0;
+    let mut valid = true;
+    for line in lines {
+        for i in 0..line.len() {
+            if re_do.is_match(&line[i..]) {
+                valid = true;
+            } else if re_dont.is_match(&line[i..]) {
+                valid = false;
+            } else if valid && re_m.is_match(&line[i..]) {
+                let cap = re_m.captures(&line[i..]).unwrap();
+                let p = |name| cap.name(name).unwrap().as_str().parse::<i32>().unwrap();
+                res2 += p("a") * p("b");
+            }
+        }
+    }
+
+    println!("res1: {}", res1);
+    println!("res2: {}", res2);
+    assert_eq!(res1, 162813399);
+    assert_eq!(res2, 53783319);
+}