2024(6): clean before fix

2024/06/part2.py

@@ -18,11 +18,25 @@ if __name__ == "__main__":
 	m = Map()
 	#m.load_map("testinput")
 	m.load_map("input")
+	loop_obstacles = []
 
 	while m.step():
-		# After each step, we can fork the map and add the obstacle.
-		print(m.pos, m.direction)
+		if verbose:
+			print(m.pos, m.direction)
 
+		# Create a copy
+		forked_map = m.copy()
+		forked_map.map[forked_map.next_pos()] = Map.Tiles.OBSTACLE.value
+		print(f"Forking at {forked_map.next_pos()}... ", end="")
+		try:
+			while forked_map.step():
+				continue
+		except Map.LoopException:
+			print("loop.")
+			loop_obstacles.append(m.next_pos())
+		else:
+			print("no loop.")
 		#m.show()
-	print(len(m.trace), m.trace)
-	print(len(set(m.trace)))
+	#print(len(m.trace), m.trace)
+	#print(len(set(m.trace)))
+	print(len(loop_obstacles))