day 15 task 2

src/tasks/day15.rs

@@ -7,9 +7,9 @@ use Direction::*;
 pub fn run() {
     let ram = load_ram("input/day15.txt");
     task1(ram.clone());
+    task2(ram.clone());
 }
 
-#[allow(dead_code)]
 fn task1(ram: RAM) {
     let (map, goal) = explore_map(ram);
     let shortest_path = map.get_shortest_path_to(Pos(0, 0), goal);
@@ -29,6 +29,21 @@ fn task1(ram: RAM) {
     );
 }
 
+fn task2(ram: RAM) {
+    let (map, oxygen) = explore_map(ram);
+    let max_distance = map
+        .positions
+        .iter()
+        .filter(|(_, c)| **c == '.')
+        .map(|(pos, _)| map.get_shortest_path_to(oxygen, *pos).len())
+        .max()
+        .unwrap();
+    println!(
+        "Task 2: time needed to reach most distant room is {} minutes",
+        max_distance
+    );
+}
+
 fn explore_map(ram: RAM) -> (Map, Pos) {
     let mut map = Map {
         positions: HashMap::new(),