day three, part two

day-3/src/main.rs

@@ -1,24 +1,54 @@
 use std::fs;
-
 use regex::Regex;
 
 pub fn parse(input: &str) -> Vec<(i32, i32)> {
-    let pattern = Regex::new(r"mul\((\d+),(\d+)\)").unwrap();
-    pattern.captures_iter(input).map(|caps| {
-        (caps.get(1).unwrap().as_str().parse().unwrap(), caps.get(2).unwrap().as_str().parse().unwrap())
-    }).collect()
+    let pattern = Regex::new(r"^mul\((\d+),(\d+)\)").unwrap();
+    let do_pattern = Regex::new(r"^do\(\)").unwrap();
+    let dont_pattern = Regex::new(r"^don't\(\)").unwrap();
+
+    let mut index: usize = 0;
+    let mut do_mul = true;
+
+    let mut parsed = Vec::new();
+
+    while index < input.len() {
+        if let Some(_) = do_pattern.captures(&input[index..]) {
+            do_mul = true;
+            index += 1;
+        } else if let Some(_) = dont_pattern.captures(&input[index..]) {
+            do_mul = false;
+            index += 1;
+        } else if let Some(caps) = pattern.captures(&input[index..]) {
+            if do_mul {
+                parsed.push((
+                    caps.get(1).unwrap().as_str().parse().unwrap(),
+                    caps.get(2).unwrap().as_str().parse().unwrap(),
+                ));
+                index += caps.len();
+            } else {
+                index += 1;
+            }
+        } else {
+            index += 1;
+        }
+    }
+
+    parsed
 }
 
 fn main() {
     let input = fs::read_to_string("input.txt").unwrap();
 
+    //let input = String::from("don't()mul(2,2)");
+    
     let parsed = parse(&input);
 
     let mut sum = 0;
 
-    for (x, y) in parsed {
-        sum += x * y;
+    for (x, y) in &parsed {
+        sum += *x * *y;
     }
 
-    println!("{sum}");
+    //println!("parsed: {parsed:?}");
+    println!("sum: {sum}");
 }