Day 2, part 2

src/pilot.rs

@@ -5,6 +5,7 @@ use std::io::prelude::*;
 pub struct Position {
     pub linear: i32,
     pub depth: i32,
+    aim: i32,
 }
 
 pub fn track_position(filename: &str) -> io::Result<Position> {
@@ -13,6 +14,7 @@ pub fn track_position(filename: &str) -> io::Result<Position> {
     let mut pos = Position {
         linear: 0,
         depth: 0,
+        aim: 0,
     };
     for line in buf.lines() {
         if let Ok(line) = line {
@@ -23,12 +25,13 @@ pub fn track_position(filename: &str) -> io::Result<Position> {
                         match op {
                             "forward" => {
                                 pos.linear += value;
+                                pos.depth += pos.aim * value;
                             }
                             "down" => {
-                                pos.depth += value;
+                                pos.aim += value;
                             }
                             "up" => {
-                                pos.depth -= value;
+                                pos.aim -= value;
                             }
                             _ => {
                                 eprintln!("Invalid operation: {}", op);