1 files changed, 34 insertions, 13 deletions

diff --git a/day12/__init__.py b/day12/__init__.py
index 52fa2e7..55545f7 100644
--- a/day12/__init__.py
+++ b/day12/__init__.py
@@ -14,28 +14,31 @@ class Map:
         self.height = len(map)
         self.width = len(map[0])
 
-        self.start = self.find_unique_position("S")
-        self.end = self.find_unique_position("E")
+        try:
+            self.start = next(self.find_position("S"))
+        except StopIteration:
+            self.start = (0, 0)
 
-    def find_unique_position(self, value: str) -> Tuple[int, int]:
+        try:
+            self.end = next(self.find_position("E"))
+        except StopIteration:
+            self.start = (0, 0)
+
+    def find_position(self, value: str) -> Iterator[Tuple[int, int]]:
         for y in range(self.height):
             for x in range(self.width):
                 if self.map[y][x] == value:
-                    return x, y
+                    yield x, y
 
     def neighbours(self, x: int, y: int) -> Iterator[Tuple[int, int]]:
         for dy in range(max(0, y - 1), min(self.height, y + 2)):
             for dx in range(max(0, x - 1), min(self.width, x + 2)):
-                current_elevation = self.elevation(x, y)
-                neigbour_elevation = self.elevation(dx, dy)
-
                 if (
                     (dy == y and dx == x)
                     or (dy == y - 1 and dx == x - 1)
                     or (dy == y - 1 and dx == x + 1)
                     or (dy == y + 1 and dx == x - 1)
                     or (dy == y + 1 and dx == x + 1)
-                    or (abs(neigbour_elevation - current_elevation) > 1)
                 ):
                     continue
                 yield dx, dy
@@ -56,12 +59,12 @@ class Map:
 
 class Assignment(BaseAssignment, ABC):
     def distance(self, map: Map, a: Tuple[int, int], b: Tuple[int, int]):
-        distance = abs(map.elevation(*a) - map.elevation(*b))
+        distance = map.elevation(*b) - map.elevation(*a)
 
         if distance > 1:
             return inf
 
-        return distance
+        return 1
 
     def heuristic(self, map: Map, a: Tuple[int, int]):
         dx = abs(map.start[0] - a[0])
@@ -120,8 +123,6 @@ class AssignmentOne(Assignment):
     def run(self, input: Iterator) -> Any:
         map = Map(map=list(input))
 
-        print(map.start, map.end)
-
         path = self.a_star(
             map,
             map.start,
@@ -134,4 +135,24 @@ class AssignmentOne(Assignment):
 
 
 class AssignmentTwo(Assignment):
-    pass
+    example_result = 29
+
+    def run(self, input: Iterator) -> Any:
+        map = Map(list(input))
+        lengths = []
+
+        for a in map.find_position("a"):
+            try:
+                path = self.a_star(
+                    map,
+                    a,
+                    map.end,
+                    distance=lambda a, b: self.distance(map, a, b),
+                    heuristic=lambda a: self.heuristic(map, a),
+                )
+
+                lengths.append(len(path) - 1)
+            except RuntimeError:
+                continue
+
+        return sorted(lengths)[0]