From 4a095e2a74f2addb1a408d105049202a8489a55b Mon Sep 17 00:00:00 2001
From: Luke Else <mail@luke-else.co.uk>
Date: Fri, 8 Dec 2023 13:50:47 +0000
Subject: [PATCH] Attempted part 2 but have made a mistake in how I
 simulatneously traverse them

---
 src/input/day08_test2  | 17 ++++----
 src/solutions/day08.rs | 90 +++++++++++++++++++++++++++++-------------
 2 files changed, 72 insertions(+), 35 deletions(-)

diff --git a/src/input/day08_test2 b/src/input/day08_test2
index 59e2d47..a8e2c98 100644
--- a/src/input/day08_test2
+++ b/src/input/day08_test2
@@ -1,9 +1,10 @@
-RL
+LR
 
-AAA = (BBB, CCC)
-BBB = (DDD, EEE)
-CCC = (ZZZ, GGG)
-DDD = (DDD, DDD)
-EEE = (EEE, EEE)
-GGG = (GGG, GGG)
-ZZZ = (ZZZ, ZZZ)
\ No newline at end of file
+11A = (11B, XXX)
+11B = (XXX, 11Z)
+11Z = (11B, XXX)
+22A = (22B, XXX)
+22B = (22C, 22C)
+22C = (22Z, 22Z)
+22Z = (22B, 22B)
+XXX = (XXX, XXX)
\ No newline at end of file
diff --git a/src/solutions/day08.rs b/src/solutions/day08.rs
index 080b34d..5bc5c4b 100644
--- a/src/solutions/day08.rs
+++ b/src/solutions/day08.rs
@@ -14,37 +14,38 @@ impl Solution for Day08 {
 
         self.populate_map(&input[2..input.len()], &mut map)?;
 
-        let mut count = 0u32;
-        let mut current = map.get("AAA").unwrap();
-        let mut found = false;
-
-        while !found {
-            for i in instructions.chars() {
-                count += 1;
-                let next: &String;
-                match i {
-                    'L' => next = &current.0,
-                    'R' => next = &current.1,
-                    _ => {
-                        continue;
-                    }
-                }
-                if next == "ZZZ" {
-                    found = true;
-                    break;
-                }
-                current = map.get(next).unwrap();
-            }
-        }
-
-        Ok(Box::new(count))
+        Ok(Box::new(self.traverse_to_end(
+            &"AAA".to_owned(),
+            &"ZZZ".to_owned(),
+            &instructions,
+            &map,
+        )?))
     }
 
     fn part2(
         &self,
-        _input: &mut Vec<String>,
+        input: &mut Vec<String>,
     ) -> Result<Box<dyn std::fmt::Display + Sync>, Box<dyn std::error::Error>> {
-        Ok(Box::new("Ready"))
+        let instructions: String = input[0].clone();
+
+        let mut map: HashMap<String, (String, String)> = HashMap::new();
+        self.populate_map(&input[2..input.len()], &mut map)?;
+
+        let mut start_points = vec![];
+        for route in &input[2..input.len()] {
+            if route.as_bytes()[2] as char == 'A' {
+                start_points.push(route.split_at(3).0.to_owned());
+            }
+        }
+
+        let mut count = 0u32;
+
+        println!("{:?}", start_points);
+        for start in start_points {
+            count += self.traverse_to_end(&start, &"Z".to_owned(), &instructions, &map)?
+        }
+
+        Ok(Box::new(count))
     }
 
     fn get_day(&self) -> u8 {
@@ -53,6 +54,8 @@ impl Solution for Day08 {
 }
 
 impl Day08 {
+    /// Given a string in the format XXX = (XXX, XXX), will populate a map witht he Xs
+    /// To create a way of traversing the route
     fn populate_map<'a>(
         &self,
         input: &[String],
@@ -78,6 +81,39 @@ impl Day08 {
 
         Ok(())
     }
+
+    /// Function to traverse the map going left and right based on given instructions
+    fn traverse_to_end(
+        &self,
+        start: &String,
+        end: &String,
+        instructions: &String,
+        map: &HashMap<String, (String, String)>,
+    ) -> Result<u32, Box<dyn std::error::Error>> {
+        let mut count = 0u32;
+        let mut current = map.get(start).unwrap();
+        let mut found = false;
+
+        while !found {
+            for i in instructions.chars() {
+                count += 1;
+                let next: &String;
+                match i {
+                    'L' => next = &current.0,
+                    'R' => next = &current.1,
+                    _ => {
+                        continue;
+                    }
+                }
+                if next.ends_with("ZZZ") {
+                    found = true;
+                    break;
+                }
+                current = map.get(next).unwrap();
+            }
+        }
+        Ok(count)
+    }
 }
 
 /// Test from puzzle input
@@ -117,6 +153,6 @@ mod test {
             .unwrap()
             .to_string();
 
-        assert_eq!(answer, "Ready");
+        assert_eq!(answer, "6");
     }
 }