From 2692f4b560f7035e73c5f1cd75e3c617e2f08756 Mon Sep 17 00:00:00 2001
From: Stefan Harmuth <pennywise@drock.de>
Date: Wed, 14 Dec 2022 19:37:03 +0100
Subject: [PATCH] Grid.getPath_BFS()

---
 tools/grid.py | 36 +++++++++++++++++++++++++++++++++++-
 1 file changed, 35 insertions(+), 1 deletion(-)

diff --git a/tools/grid.py b/tools/grid.py
index 9312d72..40d2c03 100644
--- a/tools/grid.py
+++ b/tools/grid.py
@@ -1,4 +1,5 @@
 from __future__ import annotations
+from collections import deque
 from .aoc_ocr import convert_array_6
 from .coordinate import Coordinate, DistanceAlgorithm, Shape
 from .types import Numeric
@@ -144,7 +145,7 @@ class Grid:
         return len(self.__grid)
 
     def count(self, value: Any) -> int:
-        return len([x for x in self.values() if x == value])
+        return list(self.__grid.values()).count(value)
 
     def isSet(self, pos: Coordinate) -> bool:
         return pos in self.__grid
@@ -286,6 +287,39 @@ class Grid:
         else:
             raise NotImplementedError(mode)
 
+    def getPath_BFS(self, pos_from: Coordinate, pos_to: Coordinate, includeDiagonal: bool, walls: List[Any] = None,
+                    stop_at_first: Any = None) -> Union[None, List[Coordinate]]:
+        queue = deque()
+        came_from = {pos_from: None}
+        queue.append(pos_from)
+        if walls is None:
+            walls = [self.__default]
+
+        while queue:
+            current = queue.popleft()
+            found_end = False
+            for c in self.getNeighboursOf(current, includeDiagonal=includeDiagonal, includeDefault=self.__default not in walls):
+                if c in came_from and self.get(c) in walls:
+                    continue
+                came_from[c] = current
+                if c == pos_to or (stop_at_first is not None and self.get(c) == stop_at_first):
+                    pos_to = c
+                    found_end = True
+                    break
+                queue.append(c)
+            if found_end:
+                break
+
+        if pos_to not in came_from:
+            return None
+
+        ret = []
+        while pos_to in came_from:
+            ret.insert(0, pos_to)
+            pos_to = came_from[pos_to]
+
+        return ret
+
     def getPath(self, pos_from: Coordinate, pos_to: Coordinate, includeDiagonal: bool, walls: List[Any] = None,
                 weighted: bool = False) -> Union[None, List[Coordinate]]:
         f_costs = []