Merge remote-tracking branch 'origin/main'

README.md

@@ -2,7 +2,7 @@
 
 <!-- AOC TILES BEGIN -->
 <h1 align="center">
-  2024 - 26 ⭐ - Python
+  2024 - 32 ⭐ - Python
 </h1>
 <a href="day01.py">
   <img src=".aoc_tiles/tiles/2024/01.png" width="161px">
@@ -43,4 +43,13 @@
 <a href="day13.py">
   <img src=".aoc_tiles/tiles/2024/13.png" width="161px">
 </a>
+<a href="day14.py">
+  <img src=".aoc_tiles/tiles/2024/14.png" width="161px">
+</a>
+<a href="day15.py">
+  <img src=".aoc_tiles/tiles/2024/15.png" width="161px">
+</a>
+<a href="day16.py">
+  <img src=".aoc_tiles/tiles/2024/16.png" width="161px">
+</a>
 <!-- AOC TILES END -->

day16.py

@@ -30,24 +30,39 @@ def get_best_score(grid: Grid) -> tuple[int, set[Coordinate]]:
 def get_tiles_from_all_paths(grid: Grid) -> int:
     target_score, target_path = get_best_score(grid)
     target = Coordinate(grid.maxX - 1, 1)
+
+    path_scores = {}
+    score = 0
+    facing = Coordinate(1, 0)
+    pos = Coordinate(1, grid.maxY - 1)
+    visited = set()
+    while pos != target:
+        visited.add(pos)
+        for n in pos.getNeighbours(includeDiagonal=False):
+            if n not in target_path or n in visited:
+                continue
+
+            if n - pos != facing:
+                score += 1000
+                facing = n - pos
+
+            path_scores[pos] = score
+            pos = n
+            score += 1
+
     queue = [(0, Coordinate(1, grid.maxY - 1), Coordinate(1, 0), {Coordinate(1, grid.maxY - 1)})]
-    # all_paths = set()
     visited = {}
     while queue:
         score, pos, facing, path = heappop(queue)
-        if pos in visited and score > visited[pos][0] + 1000:
+        if pos in visited and score > visited[pos] + 1000:
             continue
-        if pos in target_path and pos in visited:
-            # print(f"{pos} in target_path and visited. {score=}, {visited[pos]=}, discarding {path=}")
-            if score <= visited[pos][0] or score == visited[pos][0] + 1000:
+
+        if pos in path_scores and pos in visited:
+            if score <= path_scores[pos]:
                 target_path |= path
             continue
 
-        visited[pos] = (score, facing)
-        if pos == target:
-            target_path |= path
-            continue
-
+        visited[pos] = score
         if score >= target_score:
             continue
 
@@ -58,9 +73,6 @@ def get_tiles_from_all_paths(grid: Grid) -> int:
             add_turn = 1001 if n - pos != facing else 1
             heappush(queue, (score + add_turn, n, n - pos, path | {n}))
 
-    for p in target_path:
-        grid.set(p, "O")
-    grid.print()
     return len(target_path)