day 3 part 2

src/day03.rs

@@ -1,3 +1,4 @@
+use itertools::Itertools;
 use std::fs::read_to_string;
 
 pub fn day_main() {
@@ -24,16 +25,63 @@ fn part1(input: &str) -> RiddleResult {
         .sum()
 }
 
-fn part2(_input: &str) -> RiddleResult {
-    0
+enum Statement {
+    Enable,
+    Disable,
+    Number(i64),
+}
+
+fn part2(input: &str) -> RiddleResult {
+    let r = regex::Regex::new(r"do\(\)|don't\(\)|mul\(\d{1,3},\d{1,3}\)").unwrap();
+    let statements = r
+        .captures_iter(input)
+        .map(|c| {
+            let s = c.get(0).unwrap().as_str();
+            println!("{s}");
+
+            match s {
+                "do()" => Statement::Enable,
+                "don't()" => Statement::Disable,
+                _ => {
+                    let x = s.strip_prefix("mul(").unwrap().strip_suffix(")").unwrap();
+                    let (a, b) = x.split_once(',').unwrap();
+                    let a: i64 = a.parse().unwrap();
+                    let b: i64 = b.parse().unwrap();
+                    Statement::Number(a * b)
+                }
+            }
+        })
+        .collect_vec();
+
+    let mut enabled = true;
+    let mut result = 0;
+    for f in statements {
+        match f {
+            Statement::Enable => {
+                enabled = true;
+            }
+            Statement::Disable => {
+                enabled = false;
+            }
+            Statement::Number(i) => {
+                if enabled {
+                    result += i
+                }
+            }
+        }
+    }
+
+    result
 }
 
 #[cfg(test)]
 mod test {
     use super::{part1, part2};
 
-    const TEST_INPUT: &str = r"xmul(2,4)%&mul[3,7]!@^do_not_mul(5,5)+mul(32,64]then(mul(11,8)mul(8,5))
-";
+    const TEST_INPUT: &str =
+        r"xmul(2,4)%&mul[3,7]!@^do_not_mul(5,5)+mul(32,64]then(mul(11,8)mul(8,5))";
+    const TEST_INPUT2: &str =
+        r"xmul(2,4)&mul[3,7]!^don't()_mul(5,5)+mul(32,64](mul(11,8)undo()?mul(8,5))";
 
     #[test]
     fn test1() {
@@ -42,6 +90,6 @@ mod test {
 
     #[test]
     fn test2() {
-        assert_eq!(part2(TEST_INPUT), 0);
+        assert_eq!(part2(TEST_INPUT2), 48);
     }
 }