From: Greg Burri <greg.burri@gmail.com>
Date: Sat, 4 Dec 2021 21:23:08 +0000 (+0100)
Subject: Day 2 part 2
X-Git-Url: https://git.euphorik.ch/?a=commitdiff_plain;h=3236121d6985537b8d0646bdb5925f58fa705d1e;p=advent_of_code_2021.git

Day 2 part 2
---

diff --git a/src/day02.rs b/src/day02.rs
index 44f8ce3..732d179 100644
--- a/src/day02.rs
+++ b/src/day02.rs
@@ -7,6 +7,7 @@ pub enum Movement {
 
 pub struct Position {
     pub horizontal: i32,
+    pub aim: i32,
     pub depth: i32,
 }
 
@@ -28,12 +29,15 @@ pub fn parse_movements(movements: &str) -> Vec<Movement> {
 }
 
 pub fn get_final_position(movements: &[Movement]) -> Position {
-    let mut pos = Position { horizontal: 0, depth: 0 };
+    let mut pos = Position { horizontal: 0, aim: 0, depth: 0 };
     for m in movements {
         match m {
-            Movement::Forward(d) => pos.horizontal += *d as i32,
-            Movement::Down(d) => pos.depth += *d as i32,
-            Movement::Up(d) => pos.depth -= *d as i32,
+            Movement::Forward(d) => {
+                pos.horizontal += *d as i32;
+                pos.depth += pos.aim * *d as i32;
+            },
+            Movement::Down(d) => pos.aim += *d as i32,
+            Movement::Up(d) => pos.aim -= *d as i32,
         }
     }
     pos
@@ -69,10 +73,21 @@ mod tests {
                  forward 2"
             );
         let final_position = get_final_position(&commands);
-        assert_eq!(final_position.horizontal * final_position.depth, 150);
+        assert_eq!(final_position.horizontal * final_position.aim, 150);
     }
 
     #[test]
     fn part2() {
+        let commands =
+            parse_movements(
+                "forward 5
+                 down 5
+                 forward 8
+                 up 3
+                 down 8
+                 forward 2"
+            );
+        let final_position = get_final_position(&commands);
+        assert_eq!(final_position.horizontal * final_position.depth, 900);
     }
 }
\ No newline at end of file
diff --git a/src/main.rs b/src/main.rs
index eb070cb..e3a099a 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -14,7 +14,7 @@ fn day01() -> String {
 fn day02() -> String {
     let movements = day02::parse_movements(&fs::read_to_string("data/day02.input").unwrap());
     let final_position = day02::get_final_position(&movements);
-    format!("part1: {}, part2: {}", final_position.horizontal * final_position.depth, "")
+    format!("part1: {}, part2: {}", final_position.horizontal * final_position.aim, final_position.horizontal * final_position.depth)
 }
 
 fn format_micros(t: u128) -> String {