day20 part1 fast

src/tasks/day20.rs

@@ -13,16 +13,17 @@ pub fn task1() {
     add_default_neighbors_for_room(&mut map, Point(0, 0));
     parse_input(&mut map, &input, Point(0, 0));
 
-    print_map(&map);
+    // print_map(&map);
 
     println!("Most distant point: {:?}", longest_shortest_path(&map, Point(0,0)));
 }
 
-fn parse_input(map: &mut HashMap<Point, Tile>, input: &str, position: Point) {
+/// Returns the end points of the parsed input
+fn parse_input(map: &mut HashMap<Point, Tile>, input: &str, position: Point) -> HashSet<Point> {
     // println!("{}, {:?}", input, position);
     if input == "$" {
         println!("End of the road.");
-        return;
+        return vec!(position).into_iter().collect();
     }
     let mut position = position;
     let mut input = input;
@@ -31,15 +32,23 @@ fn parse_input(map: &mut HashMap<Point, Tile>, input: &str, position: Point) {
         match c {
             '(' => {
                 let (parts, rest) = split_parts(&input);
-                // println!("{:?}", parts);
-                // println!("{:?}", rest);
+                let mut middle_points: HashSet<Point> = HashSet::new();
                 for part in parts {
-                    let mut flattened = String::with_capacity(part.len() + rest.len());
-                    flattened = flattened.add(part);
-                    flattened = flattened.add(rest);
-                    parse_input(map, &flattened, position);
+                    if part.len() > 0 {
+                        for x in parse_input(map, part, position) {
+                            middle_points.insert(x);
                         }
-                break;
+                    }
+                }
+                let mut end_points: HashSet<Point> = HashSet::new();
+                for point in middle_points {
+                    if rest.len() > 0 {
+                        for x in parse_input(map, rest, point) {
+                            end_points.insert(x);
+                        }
+                    }
+                }
+                return end_points;
             }
             'N' => {
                 position = Point(position.0, position.1 - 2);
@@ -65,13 +74,14 @@ fn parse_input(map: &mut HashMap<Point, Tile>, input: &str, position: Point) {
                 map.insert(Point(position.0 + 1, position.1), Door);
                 input = &input[1..];
             }
-            '$' => return,
+            '$' => break,
             c => panic!(
                 "Stumbled upon a '{}' when reading input where it shouldn't be",
                 c
             ),
         }
     }
+    vec!(position).into_iter().collect()
 }
 
 /// Splits the input by '|', but only by those that are not enclosed by further parenthesises.