Finished part 2 of day 2

advent_of_code/2.rs

@@ -28,7 +28,7 @@ fn main(){
 
     let mut depth = 0;
     let mut position = 0;
-    for (direction, distance) in instructions {
+    for (direction, distance) in &instructions {
         match direction.as_str() {
             "forward" => position += distance,
             "up" => depth -= distance,
@@ -38,4 +38,27 @@ fn main(){
     }
 
     println!("Position of {} * depth of {} equals {}", position, depth, position * depth);
+
+    
+    // Now for the second part of day 2
+    // So instead of just adding to the depth immediately through the up and down commands, we now use
+    // a so-called aim
+
+    depth = 0;
+    position = 0;
+    let mut aim = 0;
+
+    for (direction, distance) in &instructions {
+        match direction.as_str() {
+            "forward" => {
+                depth += aim * distance;
+                position += distance
+            },
+            "up" => aim -= distance,
+            "down" => aim += distance,
+            s => println!("Stumbled upon unknown input: {}", s),
+        }
+    }
+
+    println!("Position of {} * depth of {} equals {}", position, depth, position * depth);
 }